At last, a play that you should see if you have not read the book or seen the 2016 film, since this is a plot that is built on uncertainty and lack of knowledge, and is enjoyed as the audience grapple with the same challenge as the main protagonist trying to put together the puzzle pieces of a missing person. Paula Hawkins’ novel has been adapted for the stage by Rachel Wagstaff and Duncan Abel and creates a very tense, taut mystery that keeps you guessing as the twist and turns of the characters are slowly recalled and the full picture emerges.

The staging design by Adam Wiltshire creates a very fluid environment in which meetings and interviews are interwoven with memories and flashbacks, which are enhanced by Dan Light’s video design to unpack the mystery of the disappearance of Megan Hipwell. At the centre of the play is Rachel who glimpses Megan and her husband Scott on her daily train journey to work and fantasises about them as a couple, Jess and Jason. When she awakes from another drunken blackout with a cut to her head and blood on her hands and hears the news that Megan has gone missing, she can’t be sure what role she played in the disappearance. In the second half, there are two brilliantly creative theatrical pivotal moments that the setting elegantly enables (to say more would be a spoiler!)

Director Loveday Ingram cleverly uses the open staging with see-through panels and raised upstage platform to make us feel the same sense of confusion and bewilderment at what is reality and what is fantasy as Rachel. Scenes feel half remembered with only small details visible. A drinks cabinet defines Scott’s home, a rug: Tom’s lounge , a chair: Kamal’s surgery and a mattress: Rachel’s bedsit. Transitions between scenes add to the fuzziness with shadowy characters in drunken binges covering the change of location. The first act slowly builds the characters and the tensions between them before the second act explodes into a brilliant tense climax that is every bit as good as an Agatha Christie reveal.

Joanna van Kampen is magnificent as Rachel, on stage throughout, indulging in bouts of drunken escapism, fearful of what she might have done in a period of blackout but still harbouring a passion and need for affection. Is she a victim, the perpetrator of some ghastly deed or an innocent bystander? As she explores the evidence by retracing steps and interviewing the other characters she seems one thought ahead of the policeman, DI Gaskill (Jason Merrells), or is someone else feeding into her paranoia and spinning a web around her? Her uncertainty over who to believe and what happened is transferred to the audience and creates a gripping tense finale.

Jonathan Firth plays Tom, Rachel’s ex-husband, now remarried to Anna (Phoebe Pryce) who together live just a few houses away from Megan and her husband, Scott (Samuel Collings). Tom has moved on from his first marriage but seems to still care for Rachel while Anna is frustrated by the ex’s constant contact with her husband. Another suspect emerges in Kamal (Tiran Aakel), a cool calm psychiatrist who may have learned more truths in his therapy sessions but should not breach the ethical client confidentiality. Each character is well drawn with a believable upright façade and occasional hints of something darker and more sinister.

Some of the dialogue seems a little stilted at times, perhaps deliberately so, but the writer creates a series of triangulated relationships and meetings or flashbacks through which backstories are revealed, movements on the night of Megan’s disappearance and alibis. The lighting - designed by Jack Knowles - helps switch between reality and recalled memory. There are some unexpected laughs, perhaps just to relieve tension such as when Gaskill explains that bodies sometimes “looked better dead than when they were alive” and another character rather tellingly states that you “can’t believe anything anyone says!”

This play is based on a best-selling thriller and if you have read the book and recall the truth, you will undoubtedly see what is happening on stage differently and can admire the storytelling and staging but if you - like me - have come to this fresh without prior knowledge, then it is the story that builds tension and sympathy as the evidence is revealed while sustaining the uncertainty. Doubts are sowed, surprises revealed and red herrings dropped as you constantly reassess who said what, when and where and that makes it a thrilling night at the theatre.

**** Four stars

Reviewed by: Nick Wayne

The Girl on the Train plays at Salisbury Playhouse until 11 November, with further information here.