There really was a Camp Siegfried in New York State in 1938. American teenagers of German descent spent their summer there, doing boy scoutish things while absorbing racist ideology through their pores, and it really did have a Hitler Street running through it.

That’s the factual underpinning of Bess Wohl’s thoughtful, sensitive and fiercely political play now running at the Old Vic.

There are just two characters.  He is 17, all noisy, hearty masculinity.  She is 16, all gawky, precious self-loathing: “I’m just a caterpillar. One day I’ll be a butterfly, if I don’t get stamped on first.” They meet, they fall in love, they hear the Fuehrer’s call to populate the world with Aryan babies, and they set to work to do his bidding.

She sees the politics behind the camp, and likes it. He doesn’t see it: he thinks all the singing and discipline is just about camp spirit. She is picked as the leader to make the big speech to the camp which is the turning point of the play, and in which she says: “America can be great again.”  This is much more than a facile nod to the era of Trump. It’s a summoning up of the demons that made Nazi Germany, an invitation to them to remake America.

After that speech they go home, and it would be a spoiler to tell you what happens to their relationship.  But I will tell you that along the way, she meets a kindly doctor and his wife.  We are not told that the couple are Jewish, but one of their kindnesses is that the doctor’s wife feeds her chicken soup with some dumplings in it.  “Is this love?” our heroine wants to know.