The Mousetrap, St Martin's Theatre, London

Since November 1952, Agatha Cristie's play The Mousetrap has been running continually in London's West end theatreland. It's the longest running play anywhere in the world.

It's been at the St Martin's Theatre since March 1974.

When you go and see it, you are asked at the end not to say who the murderer is, so I won't.

The play began life as a 1947 radio play called Three Blind Mice based on one of Agatha Christie's short stories.

When she wrote the play, Christie gave the rights to her grandson Matthew Prichard as a birthday present. Under those rules, only one version of the play can be performed each year outside of the West End, and no film adaptation can be made until the West End production has been closed for at least six months.

The play had to be renamed to avoid confusion with an earlier play of the same name. Anthony Hicks, Christie's son-in-law suggested The Mousetrap from a reference in Shakespeare's Hamlet.

In Act 3, scene 2, Claudius asks Hamlet the name of the play the court has just seen, and Hamlet answers The Mousetrap.

"CLAUDIUS
What do you call the play?

HAMLET
...
The Mousetrap. Why on earth is it called that, you ask? It’s a metaphor. This play is about a murder committed in Vienna. Gonzago is the duke’s name, and his wife is Baptista. You’ll see soon enough. It’s a piece of garbage, but who cares? You and I have free souls, so it doesn’t concern us. Let the guilty wince. We can watch without being bothered."

This is the character list:

Mollie Ralston – Proprietor of Monkswell Manor, and wife of Giles.
Giles Ralston – Husband of Mollie who runs Monkswell Manor with his wife.
Christopher Wren – The first guest to arrive at the hotel, Wren is a hyperactive young man who acts in a very peculiar manner. He admits he is running away from something, but refuses to say what. Wren claims to have been named after the architect of the same name by his parents.
Mrs Boyle – A critical older woman who is pleased by nothing she observes.
Major Metcalf – Retired from the army, little is known about Major Metcalf.
Miss Casewell – A strange, aloof, masculine woman who speaks offhandedly about the horrific experiences of her childhood.
Mr Paravicini – A man of unknown provenance, who turns up claiming his car has overturned in a snowdrift. He appears to be affecting a foreign accent and artificially aged with make-up.
Detective Sergeant Trotter – The detective role during the play. He arrives in a snow storm and questions the proprietors and guests.