When the biggest laugh of the night is generated by a stranger innocently referring to an elegant lady’s secret lover as her father; when a convoluted admission of love provokes a round of applause befitting a boundary at cricket; when a 180 degree slap misses its target by feet not inches and the intended victim falls to the ground like a sack of spuds; it’s drama, Jim, but not as we know it.

And if it is drama, it’s very much of the melo- variety. For despite the best efforts of the sterling cast – led by Lorna Fitzgerald as Iris and Matt Barber as Max – Antony Lampard’s farcical adaptation of Hitchcock’s 1938 thriller (which itself was based on a novel by the long-forgotten crime writer Ethel Lina White) is very much a museum piece as the stock characters within the well-made play structure are so of another time and place that their relevance and appeal, like their accents, is clipped.

Juliet Mills plays the titular “queer old bird” who’s a “trifle whimsical”. So much so that she loses her spectacles, loses her luggage and to complete the hat trick – does a Theresa May at the dispatch box after another Brexit defeat – and loses her self. Vanishing without trace.

Only the betrothed Iris remembers meeting Miss Froy: they shared tea for two, Harriman’s Herbal, so good that “a million Mexicans drink it”. Or did an accidental knock on her head prior to boarding provoke hallucinations? Or do one of her fellow passengers – who include an irascible Italian magician (Mark Carlisle), a stern neurologist (Maxwell Caulfield), a prominent lawyer in hiding (Philip Lowrie) and two cricket bores (Robert Duncan and Ben Nealon) – hold a grudge?

The tone is light, the action pacy and the performances choreographed to a delightful tee – Matt Barber in particular eking out farce where none should be. But the staging and direction, like the story and the structure, are solid but unremarkable. Vanishing from memory as quickly as Miss Froy.

Peter Callaghan