Charles Lenox, Victorian gentleman and armchair explorer, likes nothing more than to relax in his private study with a cup of tea, a roaring fire and a good book. But when his lifelong friend Lady Jane asks for his help, Lenox cannot resist the chance to unravel a mystery. Prudence Smith, one of Jane's former servants, is dead of an apparent suicide. But Lenox suspects something far more sinister: murder, by a rare and deadly poison.

June 1933. Independent, young Kitty Underhay has been left in charge of her family’s hotel, The Dolphin, on the tranquil English coast. But when several rooms are broken into and searched, including Kitty’s own, she quickly realizes that something out of the ordinary is afoot at the hotel. Soon, rumors are flying in the cozy town that someone is on the hunt for a stolen ruby. A ruby that Kitty’s mother may well have possessed when she herself went missing during the Great War.

The Earl of Wrexford possesses a brilliant scientific mind, but boredom and pride lead him to reckless behavior. He does not suffer fools gladly. So when pompous, pious Reverend Josiah Holworthy publicly condemns him for debauchery, Wrexford unsheathes his rapier-sharp wit and strikes back. As their war of words escalates, London's most popular satirical cartoonist, A. J. Quill, skewers them both.

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...

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.

England, 1920. Eleanor Swift has spent the last few years travelling the world: taking tea in China, tasting alligators in Peru, escaping bandits in Persia and she has just arrived in England after a chaotic 45-day flight from South Africa. Chipstone is about the sleepiest town you could have the misfortune to meet. But then, from the edge of a quarry, through the driving rain, Eleanor is shocked to see a man shot and killed in the distance. Before she can climb down to the spot, the villain is gone and the body has vanished.

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 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.

It's 1811, and the threat of revolution haunts the upper classes of King George III's England. Then a beautiful young woman is found savagely murdered on the altar steps of an ancient church near Westminster Abbey. A dueling pistol found at the scene and the damning testimony of a witness both point to one man - Sebastian St. Cyr, Viscount Devlin, a brilliant young nobleman shattered by his experience in the Napoleonic Wars.

Miss Busby helped Major Heathcliff Lennox solve a series of murders at Bloxford in the Cotswolds. Now, she finds herself drawn into a new murder, but this time, it's just her, and she must rely on her sharp mind and sharper wits to catch a Cotswolds killer, along with a handsome police inspector and a reporter who's keen to make her mark.

When a maid in the upper class Ellison household is strangled, Inspector Pitt is called in to investigate. He finds a world ruled by strict manners and social customs, where the inhabitants of the Ellison's neighborhood appear to be more outraged by the thought of scandal than they are by murder. Inspector Pitt finds a most unlikely ally in Charlotte, the Ellison's spirited daughter. But as the murders continue, Charlotte and Pitt find themselves drawn together by more than the investigation.

Ian Rutledge returns to his career at Scotland Yard after years fighting in the First World War. Unknown to his colleagues he is still suffering from shell shock, and is burdened with the guilt of having had executed a young soldier on the battlefield for refusing to fight. A jealous colleague has learned of his secret and has managed to have Rutledge assigned to a difficult case which could spell disaster for Rutledge whatever the outcome. A retired officer has been murdered, and Rutledge goes to investigate.

Cherringham - a quiet town in the Cotswolds. Nothing ever happens there, or so it seems - until one morning a woman's body is found in the river. A terrible accident, according to the police. But is this true? Sarah believes there must be more to it. In Jack, a former NYPD homicide detective, she finds a partner who is willing to start investigating with her. They soon find out that things are not as clear as the police want them to be ... This first - of many cases brings Sarah and Jack together in an unlikely partnership.

The daughter of a distinguished soldier, Bess Crawford follows in his patriotic footsteps, volunteering to serve her country as a nurse during the Great War. In 1916 she promises Lieutenant Arthur Graham that she will carry his dying request to a brother. When Bess arrives at the Graham house in Kent, Jonathan Graham listens to his brother's last wishes with surprising indifference.

Chief Inspector Armand Gamache of the Surêté du Québec and his team of investigators are called in to the scene of a suspicious death in a rural village south of Montreal. Jane Neal, a local fixture in the tiny hamlet of Three Pines, just north of the U.S. border, has been found dead in the woods. The locals are certain it’s a tragic hunting accident and nothing more, but Gamache smells something foul in these remote woods, and is soon certain that Jane Neal died at the hands of someone much more sinister than a careless bowhunter.