It’s a love triangle – of sorts. Two men Jules (Samuel Collins) who’s German and Jim (Alex Mugnaioni), a Frenchman, meet in Paris, become close friends and share their girlfriends in pursuit of establishing some basic truths about feeling and love. Then, as the action darts around Europe spanning 20 years into the 1930s, Kath (Patricia Allison) comes along.

Wertenbaker’s dialogue is lively and often funny but jokes such as “I’m French. We invented freedom” wear thin after a while. Three fine actors, however, do their best with it. Patricia Allison, in particular, as the charismatic, free-thinking, feisty Kath, finds an attractive translucent purity in the character.

During a play which runs 90 minutes, I spent the first half hour noticing that Stella Powell-Jones, Jermyn Street’s new artistic director and director of this show, is clearly not afraid of stillness. Then it began to feel too static. There are a lot of quite long speeches spoken by characters addressing each other across a space without movement. Sometimes they’re meant to be letters or narrative interjections and that’s fine but when it’s dialogue it’s not. Maybe this awkwardness accounts for the several nervous stumbles in the delivery of the lines on press night.

Mugnaioni is well cast because he looks imposing which is what his role needs. As the tension between the three of them deepens and twists he becomes convincingly anguished. Collins’s character, in contrast, remains more dispassionate. He’s an academic translator and pretty focused on work but he’s Jewish and plausibly ignoring the threats around him as time moves on. It’s a strong performance.

There’s a running theme in this play about water and drowning. Isabella Van Braekel’s set, which comprises impressionistic blue swirls daubed on off-white “paper”, supports that although I was initially puzzled and then irritated by the two opaque screens, suspended on quasi curtain track continually moved back and forth across the stage. Her costume designs, however, particularly for Allison are stunningly elegant.  Also delightful is Chris McDonnell’s evocative lighting and the special effect which suggested an underwater scene of Allison swimming.