What happened to Paul in Madagascar? He went missing in Madagascar. Or did he? Three people converge on a hotel bedroom in Rome to give their versions of the disappearance, and paint a portrait of an idealist, a man about town, a misfit, a brother and son, an enigma.

American playwright JT Rogers can certainly grip an audience, as he proved with his thriller about the Rwandan civil war, The Overwhelming, at the National Theatre a few years ago. And he really can write.

This time though, despite an attentive, beautifully acted production by Tom Littler for Theatre 503 (the last time I went there, it was still the Latchmere) and Primavera, you have to spend so much time working out who’s who and what’s what that you soon start muttering, “Why, why?”

The words are divided between three witnesses in different time periods: Paul’s wealthy, culturally conscious mother, Lilian (Sorcha Cusack), speaking five years ago; his devastated twin sister June (Miranda Foster), in her night-dress, just a few days ago; and, in the present, a hale and hearty colleague of Lilian’s dead husband, and her lover, Nathan (Barry Stanton).

A shocking speech, about the mass rape and murder of some African schoolgirls, pierces the chatter and reminiscence like a knife, but there is also a constant undertow of mystery and apprehension in the narrative, something akin to the sensation you get when reading a Patricia Highsmith novel; this Paul (also, confusingly, known as Gideon) is very Tom Ripley.

With such fine actors as these, the play shimmers in the reflective, steely splendour of Morgan Large’s design, dominated by a big white bed in the hotel room, where the characters prowl, sit down and circulate like shadows in their own story.

The actors also fill in some neat comedy passages as tourists and travellers. But the final focus is on the disappointments of mother and sister, and the blustery attempts at understanding and conciliation by Nathan. It’s an unusual, novelistic play, more intriguing than fully rewarding.