Third Girl by Agatha Christie

Three young women share a London flat. The first is a coolly efficient personal secretary; the second is an artist; and the third interrupts Hercule Poirot’s breakfast of brioche and hot chocolate insisting that she is a murderer – and then promptly disappears.

Slowly, Poirot learns of the rumours surrounding the mysterious third girl, her family – and her disappearance. Yet hard evidence is needed before the great detective can pronounce her guilty, innocent or insane…

‘And how did you know me, may I ask? What made you recognise me?’ ‘Your moustache,’ said Norma immediately. ‘It couldn’t be anyone else.’ He was gratified by that observation and stroked it with the pride and vanity that he was apt to display on these occasions.
Hercule Poirot, Third Girl

More about this story

One of Poirot's latest appearances, Third Girl was published by Collins Crime Club in November 1966 with the American first edition appearing the following year - but after a condensed version with a photographic montage had been published in the April issue of Redbook magazine.

There is the usual double-take surprise solution centring round a perhaps rather artificial identity problem; but the suspense holds up all the way. Dialogue and characters are lively as flies. After this, I shan't be a bit surprised to see A.C. wearing a mini-skirt.
The Observer

This story is relatively unusual for a later Agatha Christie in that Poirot is present more or less from the beginning of the case. Ariadne Oliver and Miss Lemon also feature and there are a great deal of amusing references to Poirot's age and the fact that he is no longer well known as a detective, now that the world has entered the Swinging Sixties.

Did you know?

The novel was adapted by Peter Flannery for ITV and was filmed with David Suchet as Poirot and Zoë Wanamaker as Ariadne Oliver in 2008. The story was reset in the 1930s to bring it inline with the rest of the TV series.