Beautiful young Elinor Carlisle stands serenely in the dock, accused of the murder of Mary Gerrard, her rival in love. The evidence is damning: only Elinor had the motive, the opportunity, and the means to administer the fatal poison. Yet, inside the hostile courtroom, one man still presumes Elinor is innocent until proven guilty: Hercule Poirot, who is all that stands between Elinor and the gallows.

Mrs McGinty died from a brutal blow to the back of her head. Suspicion fell immediately on her shifty lodger, James Bentley, whose clothes revealed traces of the victim's blood and hair. Yet something was amiss: Bentley just didn't look like a murderer.

It was not unusual to find the beautiful bronzed body of the sun-loving Arlena Stuart stretched out on a beach, face down. Only, on this occasion, there was no sun...she had been strangled. Ever since Arlena's arrival at the resort, Hercule Poirot had detected sexual tension in the seaside air. But could this apparent 'crime of passion' have been something more evil and premeditated altogether?

Hercule Poirot stood on the cliff-top. For here, many years earlier, there had been a tragic accident: the broken body of a woman was discovered on the rocks at the foot of the cliff. This was followed by the grisly discovery of two more bodies, a husband and wife, shot dead. But who had killed whom? Was it a suicide pact? A crime of passion? Or cold-blooded murder?

Three single girls shared the same London flat. The first worked as a secretary; the second was an artist; the third, who came to Poirot for help, disappeared, convinced she was a murderer. Now there were rumours of revolvers, flick-knives, and blood stains. But, without hard evidence, it would take all Poirot's tenacity to establish whether the third girl was guilty, innocent - or insane.

Late one night, two teachers investigate a mysterious flashing light in the sports pavilion, while the rest of the school sleeps. There, among the lacrosse sticks, they stumble upon the body of the unpopular games mistress, shot through the heart from point blank range.

A few weeks after marrying an attractive young widow, Gordon Cloade is tragically killed by a bomb blast in the London blitz. Overnight, the former Mrs Underhay finds herself in sole possession of the Cloade family fortune. Shortly afterwards, Hercule Poirot receives a visit from the dead man's sister-in-law, who claims she has been warned by "spirits" that Mrs Underhay's first husband is still alive.

As instructed, stenographer Sheila Webb let herself into the house at 19 Wilbraham Crescent. It was then that she made a grisly discovery: the body of a dead man sprawled across the living-room floor. What intrigued Poirot about the case was the time factor. Although in a state of shock, Sheila clearly remembered having heard a cuckoo clock strike 3.00. Yet, the four other clocks in the living room all showed the time as 4.13. Even more strange: only one of these clocks belonged to the owner of the house.

When Cora is savagely murdered with a hatchet, the extraordinary remark she made the previous day at her brother Richard's funeral suddenly takes on a chilling significance. In desperation, the family solicitor turns to Hercule Poirot to unravel the mystery.

Mr Shaitana was famous as a flamboyant party host. Nevertheless, he was a man of whom everybody was a little afraid. So, when he boasted to Poirot that he considered murder an art form, the detective had some reservations about accepting a party invitation to view Shaitana's private collection.

The house guests at Styles seemed perfectly pleasant to Captain Hastings. There was his own daughter, Judith; an inoffensive ornithologist called Norton; dashing Mr Allerton; brittle Miss Cole; Doctor Franklin and his fragile wife, Barbara; Nurse Craven; Colonel Luttrell and his charming wife, Daisy; and the charismatic Boyd-Carrington. So Hastings was shocked to learn from Hercule Poirot's declaration that one of them was a five-times murderer.

Lucy Angkatell invited Hercule Poirot to lunch. To tease the great detective, her guests stage a mock murder beside the swimming pool. Unfortunately, the victim plays the scene for real. As his blood drips into the water, John Christow gasps one final word: "Henrietta". In the confusion, a gun sinks to the bottom of the pool. Poirot's enquiries reveal a complex web of romantic attachments. It seems everyone in the drama is a suspect, and each a victim of love.

Everyone blamed Emily's accident on a rubber ball left on the stairs by her frisky terrier. But the more she thought about her fall, the more convinced she became that one of her relatives was trying to kill her.

Little did Anthony Cade suspect that a simple errand on behalf of a friend would make him the centrepiece of a murderous international conspiracy. Someone would stop at nothing to prevent the monarchy being restored in faraway Herzoslovakia. The combined forces of Scotland Yard and the French Surete can do no better than go in circles - until the final murder at Chimneys, the great country estate that yields up an amazing secret.

In appearance Hercule Poirot hardly resembled an ancient Greek hero. Yet, reasoned the detective, like Hercules he had been responsible for ridding society of some of its most unpleasant monsters. So, in the period leading up to his retirement, Poirot made up his mind to accept just 12 more cases: his self-imposed "labours". Each would go down in the annals of crime as a heroic feat of deduction.