This is the very first Poirot/Hastings story. Set in 1916, we meet Captain Hastings as he is invalided out of the Great War and goes to convalesce at Styles Court, the family home of his great friend, John Cavendish. By an extraordinary coincidence, billeted in the village is a brilliant little retired detective with an egg-shaped head, who made a considerable impression on the Captain when he was in Belgium. Styles is not a happy household and in the blistering summer heat, tensions mount.

Still in the formative years of his career, Hercule Poirot faces a most taxing case: who killed Lord Cronshaw? Was Coco Courtenay's death on the same night a mere coincidence? And did she deliberately take an overdose of cocaine?

Mrs Packington felt alone, helpless, and utterly forlorn. But her life changed when she stumbled upon an advertisement in The Times/i> which read: "ARE YOU HAPPY? IF NOT, CONSULT MR PARKER PYNE". Equally adept at putting together the pieces of a marriage or the fragments of a murder mystery, Mr Parker Pyne was possibly the world's most unconventional private eye, and certainly its most charming.

The Secret Adversary, which is the first novel in the series that follows Tommy and Tuppence, chronicles the pair's quest to find a mysterious woman who goes by the name of Jane Finn. Earlier in 1915, Jane Finn had been given a secret document while aboard the Lusitania, which was sunk due to a torpedo hit. That document was a treaty, and Jane was entrusted by the stranger who gave it to her to deliver it to the American Embassy located in London. Years later, the document has still never been delivered....

Little did Anthony Cade suspect that an errand for a friend would place him at the center of a deadly conspiracy. Drawn into a web of intrigue, he begins to realize that the simple favor has placed him in serious danger.