A decade or so ago, Joanna Murray-Smith was at pains to stress that the protagonist of her play The Female Of The Species was not intended to be Germaine Greer. She can’t really take the same tack with Switzerland regarding Patricia Highsmith, as her protagonist is a brilliant but unlikeable crime novelist most famous for creating the character of amoral killer Tom Ripley. Also, she’s called Patricia Highsmith. Bit of a giveaway, that one.

It’s not the only giveaway in the play. When young Edward Ridgeway arrives chez Highsmith in Locarno, tasked by her New York publishers with persuading her to agree to write one more Ripley novel, the imbalance of power and temperament between the two is so huge that the only hope of any dramatic progress is for Edward either to do a hell of a lot of sudden developing or to turn out not to be what he seems. And at this point, without explicitly blurting out any spoilers, let me just say that what you’re probably thinking is quite right.

Murray-Smith seems unconcerned with concepts such as “giveaway” or “spoilers” in any case. What her Highsmith and Edward settle down to is an exploration of the relationship between author and work, in particular between an iconic character and their creator. Highsmith’s arrogance in her latter years is useful for a two-hander play, as it means she can justifiably talk a fair bit about herself; Edward, conversely, gives away little biography and shows an increasing amount of insight into Ripley’s psychology.

Alas, not even a flinty performance by Phyllis Logan, a world away from her Downton Abbey housekeeper persona, can make these 95 minutes compelling. Murray-Smith doesn’t whitewash Highsmith, which means we get a more than generous dollop not just of her general misanthropy but particular prejudices against blacks (her word), Jews and Catholics. Her authorial talents don’t redeem her into someone we want to spend time with. Calum Finlay’s big reveal as Edward comes too late and in any case has been too thoroughly telegraphed. Lucy Bailey has respected form in directing crime novel and movie adaptations on stage (her Witness For The Prosecution is still running at County Hall), but this lacks either mystery or the Hitchcockian suspense of anticipating the inevitable.

The Ambassadors Theatre is currently in troubled waters; put it this way – on its website, beneath a graphic for Switzerland is the information that its preceding presentation is booking through to January 2019. (Its intended sale to Cameron Mackintosh to be converted into the long-mooted Sondheim Theatre for smaller musicals also fell through just this month.) When I saw it, a couple of nights after opening, the stalls were much less than half-full. This transfer isn’t drowned in its new space – the Ambassadors’ stalls capacity, at 250 or so, is only twice that of its original berth in the Ustinov studio in Bath – but it still feels like overreaching.

Written for the Financial Times.