Agatha Christie owned up to an ignorance of the means to murder, especially guns. Witness for the Prosecution suggests that knowledge of the law was not her strong point either. The play begins in a legal fairyland when a young man on a murder rap — the absurdly named Leonard Vole (Ben Nealon) — consults a barrister before he has even been charged. A turning point in the play occurs during his trial with the introduction of crucial evidence that would never be permitted in an English court.

No matter. Who expects verisimilitude in a Christie work? Excitement and puzzles are all we demand, and these are supplied in good measure in a play the Queen of Crime considered her best — not excepting the one still coining it after 57 years in the West End.

In its seventh offering since 2006, the ‘official’ Agatha Christie Company gives a polished account of the piece, which centres on the possibility that Vole has bumped off a rather older female admirer to cash in on her will. There is some exceptionally fine work from Denis Lill (pictured) as the charismatic defence brief Sir Wilfrid Robards QC and from Peter Byrne’s Mr Justice Wainwright who, while seeming to be the archetypal, out-of-touch judge (“What is a strawberry blonde?”), eventually proves to be all too clearly on the ball. There’s also a good turn from Lisa Kay as Vole’s Russian – which is to say, in those days of suspicious “foreigners”, highly dubious — wife.

If I tell you the drama kept me on the edge of my seat throughout, this is true in part because I was at times straining forward to discern activity within the encircling gloom of Douglas Kuhrt’s lighting design. A little more illumination, please.

This highly enjoyable show is at the Theatre Royal, Windfor, from August 16-28 and visits the Wycombe Swan from September 27.

Christopher Gray