In February 1915, the Great War is still raging on the Western Front, but in Westminster, at the centre of Hardcastle's bailiwick, a policeman is shot dead. At first, Hardcastle believes the murderer to have been a disturbed burglar. But as enquiries continue, attention focuses on an antiquarian bookseller, a struggling artist, a reporter, officers of the Royal Flying Corps, both in England and in France, and the activities of Isabel Plowman, the wife of one of them and the lover of others.

England, 1925. After years shut away from the world, former detective Lord Edgington of Cranley Hall plans a grand ball to celebrate his seventy-fifth birthday. But when someone starts bumping off members of his scheming family, the old man enlists his teenage grandson to help find the killer, before one of them is next.

The new and unusual case for Detectives Brock and Poole - One Saturday night, a masked gunman walks into a jazz club and murders the drummer. Very soon, Detective Chief Inspector Brock and Detective Sergeant Poole find themselves taking an interest in the guests at a party in Surrey's stockbroker belt, which leads them to look again at a five-year-old robbery and to interview a dozen or so armed robbers. The killer is eventually arrested, but not before numerous extra-marital affairs come to light and a bullion van is attacked...

December 1927. Mystery-writer Marius Quin has one previous bestseller, endless looming mortgage payments, and no idea how to write his next book. When his childhood friend Lady Isabella Montague invites him to an intimate New Year’s Eve party hosted by a narcissistic actor, Marius seizes upon the distraction. With his perpetually glum Basset hound along for the ride, he navigates the snowy lanes to the opulent estate of Everham Hall. As the celebrations begin, fireworks light up the sky, champagne corks pop, and then the host is murdered…

Judith Potts is 77 years old and blissfully happy. She lives on her own in a faded mansion just outside Marlow, there’s no man in her life to tell her what to do or how much whisky to drink, and to keep herself busy she sets crosswords for The Times newspaper. One evening, while out swimming in the Thames, Judith witnesses a brutal murder. The local police don’t believe her story, so she decides to investigate for herself and is soon joined in her quest by Suzie, a salt-of-the-earth dog-walker, and Becks, the prim and proper wife of the local vicar.

August, 1940. On the streets of London, locals watch with growing concern as German fighter planes plague the city’s skyline. But inside the famous Ritz Hotel, the cream of society continues to enjoy all the glamour and comfort that money can buy during wartime - until an anonymous man is discovered with his throat slashed open. Detective Chief Inspector Coburg is called in to investigate, ably assisted by his trusty colleague, Sergeant Lampson.

The village of Badger's Drift is the essence of tranquillity. But when resident and well-loved spinster Miss Simpson takes a stroll in the nearby woods, she stumbles across something she was never meant to see, and there's only one way to keep her quiet. Miss Simpson's death is not suspicious, say the villagers. But Miss Lucy Bellringer refuses to rest: her friend has been murdered. She is sure of it.

Lady Emily Hardcastle is an eccentric widow with a secret past. Florence Armstrong, her maid and confidante, is an expert in martial arts. The year is 1908 and they've just moved from London to the country, hoping for a quiet life. But it is not long before Lady Hardcastle is forced out of her self-imposed retirement. There's a dead body in the woods, and the police are on the wrong scent. Lady Hardcastle makes some enquiries of her own, and it seems she knows a surprising amount about crime investigation...

Chief Inspector Macdonald has been invited to a treasure hunt party at the house of the Graham Coombe, the celebrated publisher of Murder by Mesmerism. The clues of the hunt have been devised by Coombe's thriller-writer friends, disguised on the night under literary pseudonyms. The fun comes to an abrupt end, however, when 'Samuel Pepys' is found murdered in the telephone room in bizarre circumstances.

Spring, 1918. The Great War is at a crucial stage, the Germans are making one last push into France, and the Allies are struggling to hold them back. Battle lines are shifting, and men, and their machines, are being sent up and down the front to shore up defenses. Major Heathcliff Lennox, and his batman Greggs, are told to report to their new HQ. They set off on a sunlit day to fly the distance, but the enemy is never far away, and disaster strikes. They're sent crashing to the ground behind enemy lines, where life, death, and love await.

London, 1923. Newly minted research assistant Saffron Everleigh is the first woman to hold the position at University College of London. When she attends a dinner party for the school, she expects to engage in conversations about the university's large expedition to the Amazon. What she doesn’t expect is for Mrs. Henry, one of the professors’ wives, to drop to the floor, poisoned by an unknown toxin. Dr. Maxwell, Saffron’s mentor, is the main suspect, and evidence quickly mounts.

The year is 1920: Flying in the face of convention, legendary American adventuress Beryl Helliwell never fails to surprise and shock. The last thing her adoring public would expect is that she craves some peace and quiet. The humdrum hamlet of Walmsley Parva in the English countryside seems just the ticket. And, honestly, until America comes to its senses and repeals Prohibition, Beryl has no intention of returning stateside and subjecting herself to bathtub gin.

The story opens with the apparently accidental drowning of a sixth form student in the Norfolk countryside. As a matter of routine, or so it seems, the case passes across the desk of Detective Sergeant Smith, recently returned to work after an internal investigation into another case that has led to tensions between officers at Kings Lake police headquarters. As an ex-DCI, Smith could have retired by now, and it is clear that some of his superiors wish that he would do so.

London, 1925. With their band the Dizzy Heights, jazz musicians Ivor ‘Skins’ Maloney and Bartholomew ‘Barty’ Dunn are used to improvising as they play the Charleston for flappers and toffs, but things are about to take a surprising turn.

Three critically acclaimed recordings are joined together in this dazzling Agatha Christie Triple Bill, read by award-winning narrators Alison Larkin and James Warwick, star of the Partners in Crime TV series on Masterpiece Theater.