Das Boot ups its scope from the claustrophobia of undersea service

Previously on Das Boot. Mutiny. In the first series of the handsome U-boat drama, the claustrophobic terror of being underwater in the service of the Führer had boiled over, with Commander Klaus Hoffmann (Rick Okon) cast adrift in the Atlantic Ocean.

Things didn’t look good. But the one thing that is predictable about war is unpredictability, so it was reasonable to assume that the Atlantic would prove hospitable and deliver Commander Klaus to safety, allowing him to do battle with another plot.

In this reboot of Das Boot, there is a broadening of scope. Hoffman, as the ending of the previous series suggested, has washed up in the United States, and fallen under the influence of dubious businessman Samuel Greenwood (Vincent Kartheiser).

Kartheiser will be familiar to viewers of Mad Men as the ambitious gnome, Pete Campbell. Looking at him now — a bit older, growing into his jowls — the memory of Pete seems to have morphed with that of Succession’s zippy troll Roman Roy, who was nothing to do with Kartheiser at all.

Here, as Greenwood, Kartheiser looks like the third brother of Pete and Roman, a man whose limited abilities are matched by his flexible sense of morality, and his unquenchable sense of entitlement. He wears his Trumpiness on the surface, which leads to the obvious question: can he be trusted? Can anyone?

On the surface, the interesting thing about Das Boot is the way that a German-made drama plays around with the story of the war. The chocks-away nationalism of a British or American war film being unavailable, and a pro-Nazi viewpoint being entirely disagreeable, the drama settles instead for the contested terrain between doubt and resistance.

There are moments of terrible brutality, as you’d expect of a story set in the early months of 1943, but there’s also a sense of duty curdling into dismay.

In the US, the motivations of Greenwood and Hoffmann are far from clear, except to say that the German isn’t necessarily the worst man in the room. And when Greenwood pairs him up with another dubious German things get very messy.

The backdrop to this stuff is delivered in primary colours. A New York newspaper has the headline “Germany Encircled At Stalingrad”; there’s a sultry jazz singer, Cassandra (Rochelle Neil), who can’t get a gig or a dining reservation outside of Harlem because of American racism. All the stuff.

Meanwhile, underwater, U-822 has set sail for America under the command of wild-eyed Commander von Reinhartz (Clemens Schick) who has officially Had Enough, as a result of a disastrous mission in which he accidentally sunk a passenger ship and survived by diving his boat under the drowning wreckage.