It has passed into the realm of great British institutions, as much a highlight of the tourist trail as the Tower Of London or Madame Tussauds.
As such it is virtually critic-proof and Christie is the most successful female playwright of all time.
At her height in the early 1950s, she had three plays in the West End simultaneously: Spider’s Web, Witness For The Prosecution and The Mousetrap.
The fact that a new production of Witness For The Prosecution is running in London’s County Hall suggests her appeal has not faded.
This week I attended The Mousetrap’s 27,166th performance.
The plot is a classic old dark house mystery with a handful of strangers trapped in a snowbound manor house, one of whom is a psychotic murderer.
The interaction of the characters is far more intriguing than the plot.
Mollie and Giles Ralston (Ellie Burrow and Ed Pinker) have recently opened a guest house but pressure is mounting and their one-year-old marriage is beginning to unravel.
Shortly after they welcome their first four guests, a snowstorm renders everyone housebound.
Then young Detective Sergeant Trotter (George Evans) arrives, suspecting one of the guests of a recent murder.
By the end of the first act another murder has been committed in the house.
As Trotter attempts to identify the killer and prevent a third death, suspicion falls on each guest in turn.
Christie’s subtext, that we can never really know the truth about other people, leaves a psychological residue that lingers like a ghost.
The wonderfully evocative set is all faded grandeur and gentility, slightly worn chintz and stained glass windows through which we see snow falling.
If the denouement is a bit rushed, it is preceded by a comforting nostalgia.
I was 13 when I first saw The Mousetrap so I already knew whodunnit.
It did not spoil my enjoyment one jot.