On the five-hour drive to the docks of Buenos Aires, Claudia Osiani thought hard: do I board the cruise ship or cancel my birthday voyage? With her husband, Juan, she discussed the recent spate of deadly virus outbreaks on cruise ships in Japan and California. “This cruise is different; it will be packed with locals,” Juan reassured her, and it made them feel safer. He had sacrificed so much to provide Claudia with this fantasy of a 14-day voyage through the wilds of South America, and she loved him too much to let on that she was petrified at the thought of embarking.

It was early March 2020, and the first wave of the Covid-19 virus was spreading not only in Wuhan, China, but Italy and Spain. In the UK, cases totalled 273; in Argentina there were fewer than a dozen and it felt like a northern hemisphere issue. “We’re going so far south,” Claudia told Juan in the car. “It’s going to be a bunch of Argentinians on that ship, maybe some Chileans.”

At the docks they spotted their ship, the MS Zaandam. Christened in May 2000, the Dutch-flagged vessel had the feel of an ocean liner of a bygone age. She was steeped in the nearly 150-year history of the Holland America Line, for decades the industry leader in service and style, and known in its marketing materials as “the Spotless Fleet”.

Claudia and Juan had been together for 42 years. Claudia was a stickler for detail and liked to swim and cycle. She was an experienced psychologist, and gregarious, open to speaking her mind, making grand gestures. Juan, a soft-spoken accountant, was in many ways her opposite. His mother was an immigrant from Bath, England; his father was from the Netherlands. But they’d made it work, raising three children who’d given them nine grandchildren.

As the couple boarded, they found that almost none of the passengers came from Argentina or South America. Their hopes of cruising with people from countries spared by this new deadly virus vanished. Aboard the Zaandam were 305 Americans, 295 Canadians, 105 French, 131 Australians and 229 UK citizens.

As more than 1,200 guests and almost 600 crew settled in, the Zaandam became a buzzing community that included 10 decks, eight bars, two pools, a casino, a mini tennis court, an art gallery, a library and a performance hall with a capacity for 500. As last-minute preparations to leave were made, dancers limbered up, magicians rehearsed, members of an a cappella choir belted out tunes and a team of massage therapists were busy kneading away knots from the stress of life onshore. Few passengers were monitoring the news channels that would have alerted them that on 8 March 2020, just 48 minutes before the Zaandam’s departure, the US state department posted a warning that was as unambiguous as it was unprecedented: “American citizens, especially with underlying conditions, should not travel by cruise ship.”

Aboard the Zaandam, the musicians tuned their instruments.

The cruise was a once-in-a-lifetime chance to visit the strait of Magellan, navigate the Beagle Channel, follow Darwin’s route, and then cruise up the west coast of South America for an excursion to relive the excitement of Hiram Bingham’s 1911 “discovery” of Machu Picchu, high in the Peruvian Andes. They would end with a passage through the Panama Canal, island hop in the Caribbean and then disembark at Fort Lauderdale.

Down in the holds, the quartermasters went over the stores for the long trip. To feed all passengers and crew on a ship like the Zaandam for a long cruise typically required 60,000 kilos of vegetables, 40,000 eggs, 20,000 steaks, 16,000 cans of beer and soda, and hundreds of cases of wine. In addition to these carefully itemised supplies, another traveller was aboard the ship – a deadly stowaway probably hiding in the lungs of a passenger or a crew member.

In the run-up to the Zaandam’s departure from Buenos Aires, Holland America medical experts had dispatched advice on how to protect against coronavirus. Dr Grant Tarling delivered updates in cheery three- to five-minute videos posted on corporate websites. “Given recent events and general inquiries we have received about travellers’ health,” said Tarling, looking into the camera in one video released in late February, a map of the world behind him, “you may want to bring your own thermometer.” Tarling, the company’s lead medic, also demonstrated the correct position to sneeze, bringing his bent arm close to his nose. “If you cough or sneeze, do it into a tissue or your bent elbow.” His third piece of advice was: “Buy travel insurance.” The doctor suggested passengers read the insurance coverage closely to “make sure it is the kind ‘cancel for any reason’ and covers many unexpected travel situations, such as medical care and evacuation”.

Back at corporate headquarters, Holland America and its owner, Carnival Corporation – the world’s largest travel and leisure conglomerate with more than 100,000 employees and a stock valuation in the billions – had already dealt with the virus on several other ships. Two Carnival ships – the Grand Princess and the Ruby Princess – were suffering severe Covid outbreaks off the Pacific coasts of the US and Australia, respectively. The Diamond Princess had been hit hard in Japan a few weeks earlier, when hundreds were infected and at least nine people died.

Soon after boarding, Claudia noticed the first coughs. Once she tuned into the sound, it seemed to be everywhere. I can see these people are sick – anybody can, she thought.

Nine days into the cruise, as the world was locking down, Claudia marched down to the front desk, by the huge pipe organ. “How can the captain allow this? Allow people to gather in groups, so close to each other, if there is a pandemic all around?” she asked. Claudia urged the staff to take precautions, to protect the ship from Covid. She walked the ship, unnerved by all the older Europeans, Americans and Canadians gathering, seemingly oblivious to the threat. The gym, spa and hair salon were open, packed with people. This makes no sense, Claudia thought. Everywhere she glanced, she saw evidence of Carnival Corporation’s efforts to fulfil its brand slogan, Choose Fun.

In the tight crew quarters far closer to the waterline, workers began to succumb. Some told their supervisors; others soldiered on. Wiwit Widarto, the boat’s laundry supervisor, felt tired, his muscles aching. He assumed it must be his workload, or maybe a common cold. He and the rest of his crew were working nonstop, 10-12 hours a day, in the sweltering confines of the ship’s cramped laundry rooms, trying to keep up. More passengers and crew were spending more and more time in their cabins, which translated into piles of soiled sheets, towels and napkins.

Crew members made valiant attempts to limit the outbreak. They seemed to be everywhere, politely suggesting that passengers wash their hands or make use of the hand sanitiser stations. The self-serve buffets were shielded by Plexiglas, and servers were posted every few feet to ladle out the portions and minimise passengers’ contact with food. Even the US Centers for Disease Control and Prevention (CDC) and the World Health Organization were confused – was the virus able to live on surfaces? How long did it survive?

As the cruise entered the second week, fear was ruining the voyage for Claudia and Juan. Near the strait of Magellan, nervous locals had protested over the ship’s arrival, worried they might bring the virus to the remote Chilean city of Punta Arenas. Along with friends from Argentina, they drank tea in the dining room and avoided crowds. They were sitting near the sweeping main staircase – the one that always reminded Claudia of the one aboard the Titanic – when an announcement startled them.

“Good afternoon. This is your captain speaking from the bridge with an important announcement,” Captain Ane Smit began, addressing the entire ship. “I ask that everyone please listen closely.” The news was grim. An influenza-like respiratory virus had sickened many passengers. “Out of an abundance of caution, we must ask that you return to your staterooms as soon as you are done with lunch,” the captain continued, “where, regrettably, we are going to have to ask you to remain.”

Many cabins had less space than a one-car garage. Dozens of rooms were windowless. Claudia sat in the cabin with Juan, nervously staring out of a salt-streaked porthole, or watching television. Relying on her experience as a psychologist, she knew that anxiety, fear and depression were all rising. The uncertainty ate away at her.

Claudia Osiani at home in Argentina.

Instead of a comfortable crash pad for naps between happy hours and city tours, the cabin now felt like a cell for two. Meals, once a highlight, were now cloaked in anxiety. Lunch arrived via a disturbing, invisible operation. Claudia heard the sudden cry “Foooooooooood!”, then the clanking of a delivery cart as it was wheeled down the hall. Then at the next cabin, the cry “Foooooooood!”, and the next.

Opening the door, she found a tray on the floor. With bath soap, she washed every fork, knife and plate. When the soap ran out, she switched to shower gel for the glasses and edges of the tray, which she gingerly brought to the side of the bed. Claudia and Juan eyed the food with suspicion. They chewed cautiously, enjoying not a bite, nor a sip of the complimentary red wine. Juan and Claudia were supposed to be disembarking in three days – their original itinerary was nearly over – but now all schedules had been shredded.

Panicked by the outbreak, passengers rang and insisted on special services; Widarto made a point of going to their cabins to personally change their sheets or exchange towels. Some guests were clearly sick, but he helped them as best he could. Adding to the workload, one after another of Widarto’s staff members fell ill. He ordered them to bed, which meant he and the remaining members of staff had to work even harder. After three decades on cruise ships, Widarto was a perfectionist, and that drove him to work harder at times like these. When he called his wife, Anny, back in Indonesia, she noticed his voice was different. “You have to go to medical, to the pharmacy,” Anny said, growing more concerned. “You have to get some help.”

Widarto explained that he’d gone to the medical centre, but all they had to offer him was paracetamol. Anny was shocked. “You need to stay strong, focus on yourself, get better,” she said, attempting to raise his spirits. Widarto told her he’d do his best, but just before hanging up, he shocked his wife.

“Anny,” he said, “please pray for me.”

Widarto wore a mask and gloves when he could, but was that enough to protect against any virus left on sheets and pillowcases? Rumours flew about that Widarto had removed sheets from the bed of a guest so sickened that he was unable to walk and was transported to the medical centre in a wheelchair. Word was that the passenger had died, but no one could be sure.

Widarto faced more immediate challenges. He was losing staff at an alarming rate. Over the previous three days, they had kept getting sicker. Their cramped, sweltering workspace seemed to amplify the coughs. The two doctors aboard weren’t much help. A couple of housekeeping staff had reported to the sick bay, and returned with no more than a paracetamol and a bottle of cough syrup. Widarto was subdued as he confessed to a friend: “I can’t taste anything.”

As the Zaandam steamed north up the west coast of South America, country after country announced ever more strict precautions to protect their populations. None would take the chance of letting a cruise ship dock, despite intense efforts by the cruise line and diplomats to gain safe harbour. The crisis was growing by the day; an international pandemic – the first in a century – was declared, and airline travel was shutting down. Instead of their fantasy escape, the crew and passengers aboard the Zaandam were shunned. No one knew much about the new Covid virus, but cruise ships were assumed to be giant incubators.

Warren Hall, a South African gynaecologist who was the chief medic on the Zaandam, oversaw a sparse medical staff in the bow end of one of the lower decks. At the entrance, there was a reception and two examination rooms. The medical centre had surgical tools and medicine at the ready for emergency procedures. Down a hallway, there were four inpatient rooms, outfitted like those in a hospital.

Medical staff were experienced in treating life-threatening illnesses far from land: fatal heart attacks and falls were common among the older passengers. But when patients were in a grave condition, the ship would typically rush to port and unload the stricken individual. Now, the infirmary was awash with coughing passengers and ill crew members who lined up in the corridor, waiting their turn. Some looked as if they might topple over at any moment. Passengers and crew also crowded inside the tiny reception area. And in each of the examination rooms, a patient lay supine. The coughing was incessant. The two doctors and four nurses worked valiantly but were overwhelmed.

As the outbreak spread through the locked-down ship, family members of those trapped aboard launched social media campaigns to rescue their loved ones. They created a Facebook page and hundreds joined to share what they knew. Reporters began to interview passengers, and timelines were flooded with pleas for help. A newlywed Mexican couple on their honeymoon created a WhatsApp group. They named it Zaandam Prisoners.

With no chance to escape, Claudia returned to a familiar role: caretaking. She rang her friends on board and cheerfully chatted about the sun, the sea and the wind. Her top priority was an elderly couple who were relying on sleeping pills to cope with the stress of lockdown. She knew that in situations of extreme, prolonged stress or trauma, people tended to self-medicate with whatever was at hand: booze or, in this case, sedatives. Claudia was able to help put their minds at ease by calling over the ship’s phone with soothing, detailed descriptions of scenes outside the cabin window in what she dubbed “weather therapy”.

A TV channel featured a live camera shot from the bow of the Zaandam, displaying the open ocean in a wide-angle panorama. Rather than bringing calm and tranquillity, the live feed further emphasised to Claudia that they were ploughing the seas, destination unknown. She felt as if she were incarcerated in some kind of surreal, vaguely luxurious floating prison.

In the medical centre, the patients got sicker and sicker. John Carter, a 75-year-old from north Devon, was among the most gravely ill. For hours, he was in a critical condition. Dr Hall diagnosed bacterial pneumonia brought on by an unknown viral infection. As Carter’s breathing worsened, Hall threaded a tube into his lungs and connected him to a ventilator.

Hall had just 11 tanks of oxygen on board, and the ventilator was going through the supply rapidly. Hall knew that a flood of elderly patients with respiratory issues would necessitate far more oxygen. Without it, they might die. There was no doubt that Carter had to have it. But it wasn’t enough, and Carter died. His grieving widow was then left alone, only able to speak by phone with family. They issued a plea on her behalf: “She is obviously distressed and extremely frightened … she is struggling … and feeling unwell.”

Wiwit Widarto, the boat’s laundry supervisor, who fell ill while working onboard.

Below decks, Widarto was trying to find the strength to call Anny at their home in Batam, Indonesia. He now felt too sick to work in the stifling heat. But, as always, guests called and called, requesting fresh sheets, or just needing to talk. Widarto felt obliged to go to their aid. He put on the best face he could for Anny as he called via WhatsApp. They exchanged hellos, and Widarto tried to calm Anny down, set her mind at ease. “Please don’t be sad,” he said. “You need to be a strong mom. For the kids.”

Anny pressed him, trying to find out what was wrong. Finally, Widarto confessed that his fever was rising, and the coughing was worse than ever. He thought the limited stocks of medicine were reserved for the ill passengers and was relying on home remedies, like hot tea with lemon. Then he interrupted the conversation: he had to go. A passenger had called, requesting a fresh blanket.

Anny was shocked. Why was Widarto insisting on working? He seemed distant, taking his time before answering.

“Please, please rest,” Anny pleaded. “Please. Don’t work while you’re feeling unwell.”

“I can’t. I can’t afford to do that,” Widarto finally responded. His voice trailed off. “Lots of my staff are falling ill. Someone’s got to work.”

“Please, stay strong,” Anny said; she was crying.

Entering the third week of its odyssey, the Zaandam sailed further north up the coast of South America; a flurry of diplomatic notes whizzed back and forth as US, Canadian, French and British diplomats pressed the government of Ecuador to let the passengers get off. Thanks to a policy of hiring former navy admirals and coastguard commanders, the Holland America leadership worked smoothly with the diplomats – on many issues they spoke the same language, fought for the same goals.

But even if the Zaandam obtained clearance to let passengers disembark, there was no assurance that Holland America could win permission to fly them home. “I’ll ask our team in Quito, but early signals are bad, as gov’t has shut down movement and borders,” wrote a US diplomat in an email. “The governor of Guayaquil has been very active in denying entry.”

Few options remained. Emergency medical flights were in short supply everywhere. Wealthy individuals around the world with the means to pay $25,000 or $200,000 for a private escape had booked jets, helicopters and yachts for a swift retreat from the virus. Holland America had the cash to secure these flights, but what would be the use if the plane couldn’t land?

Navigators aboard the Zaandam, helped by Holland America executives onshore, began charting multiple options – would they be allowed through the Panama Canal? Should they head to a US port in San Diego? But the reality was clear: they were on a voyage to nowhere. Passengers largely obeyed the lockdown orders. At times, small groups would be ushered out for 15 minutes of fresh air, but seeing crew members in masks just added to the sense of danger. No one knew how many were infected, but the number of little red stickers placed on the doors of those thought to have Covid marked the spread.

As the ship anchored off the coast of Panama, reinforcements finally arrived. Carnival Corporation had ordered the Zaandam’s sister ship the Rotterdam to rush down from Mexico. It carried essential crew and was empty of passengers. The plan was to dilute the problem by moving healthy passengers off the Zaandam and on to the Rotterdam. Additional medical supplies and personnel and support crew could also be brought aboard what was now dubbed by the media “The Pariah Ship”.

Claudia was praying that she and Juan would be allowed to transfer when she heard a knock. She opened the door and a crew member wearing a gown, gloves and a face mask delivered the good news: they were among the roughly 800 passengers cleared to leave. They gathered their suitcases and sat down in a small transfer boat known as a tender. Claudia was elated to be leaving; she knew she was lucky. Their early precautions had worked, as neither she nor Juan were infected. Now they were on a circuitous but hopeful path back to their home in Argentina.

Back on the Zaandam, however, the raging outbreak had struck down scores of crew and passengers. Then on 27 March, Captain Smit took to the airwaves again – this time with the grim news that four passengers had died. One was John Carter. Another man had collapsed on his way to the bathroom and died on the floor. Another had suffocated, unable to breathe as his lungs were destroyed by Covid. Medical personnel were swamped by calls and overworked, forced to run from one cabin to another, yet still the patients waited hours, sometimes more, to be seen by a doctor.

As the Zaandam headed for Florida, mixed signals from the Trump administration stymied attempts by Holland America to find a way to get several dozen people in desperate need of medical care off the ships. It took endless rounds of negotiations between the cruise line, CDC officials, Florida state health authorities, the White House and diplomats from a dozen countries to finally develop an evacuation protocol that was acceptable to all.

Baggage handlers unload suitcases from the Zaandam in Florida.

On 2 April 2020, nearly a month after leaving Buenos Aires, a fleet of buses lined up on the docks of Port Everglades in Florida, and most passengers from both the Zaandam and Rotterdam were allowed to disembark. A row of ambulances were ready as well. One of the first people evacuated from the Zaandam was Widarto, who was now fighting for his life. Hall had done what he could, but Widarto’s condition had deteriorated, the virus destroying his lungs; he badly needed ICU care.

Within minutes, they moved Widarto down the gangway and into an ambulance. The ambulance sped off. A medical team at Broward Health Medical Center in Fort Lauderdale was waiting for him. But doctors were not optimistic: in a video call, they told Anny that her husband was losing the battle, that his lungs were filling with fluid, and that nothing they had done was stopping that deadly process. When that time came, the doctors could only revive him with the defibrillator, gambling that they could shock life back into his body. But that procedure could have devastating consequences, the doctor warned; he could end up paralysed. Anny had to make a choice: did she want him resuscitated? Or would it be kinder to let him die? She talked it over with her family and they agreed. “If he flatlines, let him die in peace,” she said. “That’s what God would want to happen. If God wanted him alive, he would be alive.” Anny was only able to see him on a video call before he died.

Two dozen passengers were medically evacuated, but hundreds more were deemed fit for travel. Bundled on to buses and dumped at airport terminals, they then crisscrossed the country and the world, and some carried the virus.

Although hundreds of passengers had walked off both the Zaandam and the Rotterdam, Claudia and Juan were told they could not disembark. Claudia waited for a few hours and then called reception. It took a moment to unravel what was happening. “Oh – we’re so, so sorry, but you will not be disembarking,” the receptionist announced cheerfully.

“What do you mean?” Claudia asked.

“There was a problem with your flight to Argentina. We need you to stay on the ship a little while longer, while we work out a solution.”

Claudia Osiani and her husband, Juan, at their home in Mar del Plata, Argentina.

The Argentinians were stuck in bureaucratic gridlock. So, too, were the hundreds of crew, as the CDC had decided it was too dangerous to let potentially infected crew members into society. The Rotterdam and the Zaandam left Florida and abandoned US territorial waters, docking instead near the Bahamas.

Day after day, the two ships sailed in what pilots call “doughnut patterns” as crew and approximately nine passengers remained locked down. With the help of the cruise line, Claudia was untangling the logistics of organising a flight back to Argentina when the captain’s voice sounded loudly over the ship’s public intercom. He appeared to be giving orders exclusively to the crew. To Claudia, it felt as if they didn’t exist; that they were ghosts on a ghost ship.

“Personnel will now move to deck two,” the captain declared. Or that’s what Claudia thought he had said. “Deck two, Juan? That’s us, right?”

Soon, a powerful chemical smell wafted into their cabin. A pungent disinfectant stench burned the back of her throat, making her wince. Claudia grabbed a face mask and burst out of the cabin, desperate to breathe fresh air. With Juan, she ran to an exit. Outside, the sun blinded them momentarily. Claudia fell to the deck, gasping for air.

Claudia spotted a surveillance camera and ran toward the tiny lens, screaming in Spanish for help. Soon, one of the ship’s officers arrived. Claudia scolded him for accidentally trying to poison them as they disinfected the ship. At first the officer didn’t understand her machine-gun Spanish, but eventually they were transferred to a new room with a private balcony. Despite the upgrade, they felt like orphans, forgotten on an empty cruise ship, with no sign of liberation.

As she entered her second month at sea, Claudia was still in lockdown, and as furious as ever. For another three weeks, they circled the Caribbean waiting for the plane to fly them home. Claudia knew that her years as a psychologist provided exactly the emotional toolkit she would need to endure this confinement. I can’t cry and throw a tantrum like a child, she thought. What surprised her, however, was how hard it was to apply her skills to a new patient: herself.

Help came in the form of her 80-year-old neighbour, a man named Tito from Uruguay, who, like clockwork every morning, strode out to his balcony, adjacent to Claudia and Juan’s room, and bellowed to the ocean: “Toooooooday ... can be a goooooooood daaaaaaay! Let’s nail it!” Sometimes Claudia joined in the screaming.

Finally, the Argentinian government resolved the logistics, and arranged for charters and sanitation “bubbles” that could safely bring Claudia and Juan, and the other citizens, back to Uruguay and Argentina. It was now late April 2020, seven weeks after Claudia and Juan boarded what was supposed to be a two-week celebratory cruise.

In a statement, a representative of Holland America Line said: “As the world’s knowledge of Covid-19 evolved over time, Holland America Line aligned with guidelines from the CDC, the World Health Organization and other local health authorities.” They said of the stories in this article: “While some claims do not match the recollection of our team members who were there, that should not diminish the importance of the story of Zaandam, its guests and crew, and people in all walks of life who dealt with the devastating first weeks of a mysterious virus. We mourn all who were lost to Covid-19, and we are thankful for those who helped bring our full fleet back to sailing today with a continued strong commitment to health and safety.”

When Claudia arrived at the door to her seaside apartment in Mar del Plata, Argentina, the country was enduring the full brunt of the viral onslaught. Thousands were sick, a rigid lockdown in place. The official death toll stood at roughly 200.

Inside her home, instead of relief, Claudia felt vulnerable. Nothing was normal. Her favourite routines were prohibited under lockdown. No more swimming with her girlfriends. No more rehearsals with the theatre group. Even the smell of her house had changed. Or had she?

Before the Zaandam odyssey, before Covid, Claudia and Juan had carefully selected an apartment with an ocean view. Their living-room windows framed a wide slice of the Atlantic. Her panorama now felt like a mocking reminder, as if she was still trapped at sea. When Claudia looked out her window, she couldn’t escape the sensation that she was on the balcony of a cruise ship. After one brief glance into the expanse of the waves, Claudia drew the curtain and told herself: “That’s enough ocean view for the moment.”