Miss Marple believes she's seen a murder in a passing-by train, yet when the police find no evidence she decides to investigate it on her own.

Actress Jane Wilkinson wants a divorce, but her husband, Lord Edgware, refuses. She convinces Hercule Poirot to use his famed tact and logic to make her case. Lord Edgware turns up murdered, a well-placed knife wound at the base of his neck. It will take the precise Poirot to sort out the lies from the alibis - and find the criminal before another victim dies.

Sir Charles Baskerville dies on the moor under mysterious circumstances and rumors abound about a demonic hound. When the American heir arrives to take charge, a family friend calls in Holmes and Watson to get to the heart of the mystery.

An upper-crust family dinner is interrupted by a police inspector who brings news that a girl known to everyone present has died in suspicious circumstances. It seems that any or all of them could have had a hand in her death. But who is the mysterious Inspector and what can he want of them?