It was only about five years ago that Tom Stoppard began to think about writing Leopoldstadt, the work that would be seen by many as his “Jewish” play, which had its opening run in the West End rudely interrupted by the coronavirus.

But if the dramatist ever thought that writing about the generation of Jews whose lives were shredded by the Nazis meant that he had ticked that box, thematically speaking, then he was wrong.

Ahead of him was The Voyage of the St Louis, his adaptation for radio of Daniel Khelmann’s play about the German ocean liner that on May 13, 1939 set sail from Hamburg bound for Cuba with 937 German Jewish refugees on board. It will be broadcast on Radio Four on May 9.

Though the ship took weeks to get there, Sasha Yevtushenko’s impressively cast Radio 4 production moves at a rate of knots. Throughout the drama one question hovers like the sword of Damocles — whether or not the Cuban authorities will allow the ship’s passengers to disembark.

The true story is elegantly framed by the idea that some of those who lived through it describe what happened from beyond their graves. Philip Glenister is the ship’s Captain Schroeder who, rarely among the gentiles represented here, views the ship’s passengers as being as deserving of humane treatment as non-Jewish cargo.

At the other end of the vessel’s hierarchy, and moral spectrum, is ship steward Otto Schiendick, an enthusiastic Nazi played by the excellent Paul Ritter with a nasal sneer that conveys a mind that is as hateful as it is small.

And caught between them are the Jews. Their fate relies on the decision of Cuba’s corrupt President Brú (Alan Corduner) and even more corrupt minister Benitez (Joseph Balderrama). Then there is Toby Jones as savvy New York lawyer Berenson who attempts to negotiate on the passengers’ behalf. He could be viewed as the cavalry who comes to the rescue, the play suggests.

But as Schiendick reminds us, he and everyone else in the play actually existed. So did all the events, even the Nazi’s secret SS mission to collect micro-film in Cuba and return with it to Germany.

So perhaps best not to place too much hope in the cavalry. Much like Stoppard’s pre-and-post Holocaust play Leopoldstadt, happy endings are not the point.

The Voyage of the St Louis is on Radio Four on May 9 at 14.45pm