On 25 April 1945, with Soviet forces closing on the area around Stutthof, those running the camp marched the remaining prisoners to the coast and ordered them onto river barges — flat-bottomed craft built for canals and estuaries, not for open water. After a few days the prisoners were put ashore on Rügen. On 3 May they were forced onto another barge and let drift into the Baltic. There was no food. Typhus was already aboard, and in the filth and crowding it spread fast. Accounts of the voyage do not entirely agree: some Danish newspaper reports from May 1945 describe a single barge for the whole crossing, most describe the transfer at Rügen; some name an SS vessel as the boat that finally took them under tow, others a civilian German tug. What is not in dispute is where the drifting ended. Two days after leaving Rügen, the barge was pulled into Klintholm Havn.

They were, almost all of them, political prisoners, and most had been taken for resistance work. Among them were several Jehovah's Witnesses, a faith the Nazi regime had banned outright. Danish Red Cross archives, drawing on an analysis made by Zygmunt Szatkowski — himself one of the prisoners on the barge — record that the largest group were Poles, followed by a large number of Russians, with smaller numbers of Czechoslovaks, Germans, Estonians, Latvians, Lithuanians, Turks and Frenchmen, and a few citizens of the Free State of Danzig. One of the Poles was carrying a United States passport. Hermine Schmidt, the German woman whose memoir Unfettered Joy records the crossing, wrote of the reception at the quay: "It was unbelievable how they welcomed us. We had lice and fleas and looked like walking skeletons but they came down to the harbour and hugged us."

Rasmus Fenger, the local doctor, went aboard almost as soon as the barge was tied up, and what he found was dysentery, typhus, tuberculosis and starvation, in a population that also had fleas to a person. The first day's problem was simply food and clean water for 370 people in a village that had neither in that quantity. Bread, milk and butter were gathered from the surrounding farms; fresh water was brought in bulk. A rescue committee formed out of the Red Cross and the Danish resistance movement. The worst cases went to the hospital at Stege or to Hotel Søbad, a few hundred metres up from the harbour, which became a temporary ward. The rest stayed on the barge for as long as ten days while community halls and hostels were found. Danish doctors and nurses worked alongside those prisoners who were well enough to help. Within days, with food and medicine, the mood aboard began to lift. This was all happening in the same week the country was celebrating its liberation.

Nineteen people could not be saved. They died over the following days of disease and starvation, having survived the camp, the march, the barge and the Baltic, and having reached help too late for it to matter. Some of them lie in the churchyard at Magleby, a few kilometres inland. Their names do not appear in the summary accounts of the rescue, which tend to lead with the number who lived. Both numbers belong to the story. Three hundred and fifty-one people walked off that barge because a fishing village decided to act; nineteen did not, and the memorial at Klintholm is careful to say so.

A memorial stone stands on the shore at Klintholm Havn, at the point where the barge came in. It was raised on 5 May 1995, fifty years to the day. The Danish inscription reads: Fra sult og nød, tortur og død / De mødte på en fremmed kyst / I hjælpsom ånd, en udstrakt hånd — from hunger and peril, torture and death, they met on a foreign shore a helping spirit, an outstretched hand. A board beside it carries explanations in four languages, and the English text honours both "those people who, with no thought for their own safety, saved the lives of 351 of the prisoners" and "those victims who never reached the outstretched hands of the rescuers of Klintholm." The survivors said it first, in a letter of thanks drafted by Szatkowski, Wysocki and Sister Hilda and printed in Møn's newspapers: "We thank you Danes for our lives... Its inhabitants received us as if we were their own." They named the people they could still remember — Mrs Mortensen of the Red Cross, Dr Fenger, Dr Mortensen, Miss Sønderskov — and apologised for the names they had lost.