July 1910. Lady Hardcastle and her tireless sidekick Flo have finally embarked on a long-overdue seaside break. But just as they’re wavering between ice creams and donkey rides, their fellow guests start to go missing - and the duo find themselves with a hysterical hotel manager and a case to solve. The first to disappear is Dr Goddard, a scientist doing something terribly top-secret for the government. 

January 1910. A journalist has been killed in a suspicious blaze. Everything points to a group of suffragettes, but the apparent culprit insists she is innocent. When Lady Hardcastle receives a letter from a suffragette requesting her urgent help, the retired spy turned sleuth knows only she stands between an accused young woman and the gallows. Evidence at the scene makes Lizzie Worrel’s innocence difficult to believe, and with the police treating it as an open-and-shut case of arson, Lady Hardcastle faces a barrage of resistance as she tries to dig out the truth.

Late October 1909, and the season of ghouls and things that go bump in the night has descended on the village of Littleton Cotterell. Lady Hardcastle and her trusted lady’s maid, Florence, find themselves hosting a colorful cast of actors whose spooky moving picture, The Witch’s Downfall, is being shown to mark Halloween. But things take a macabre turn when the first night’s screening ends with a mysterious murder, and the second night with another. One by one the actors turn up dead in ways that eerily echo their film.

September 1909, and Lady Hardcastle and her maid, Florence, have been invited to Lord Riddlethorpe’s country estate for a week of motor racing and parties. They both agree that it sounds like a perfectly charming holiday. But when one of the drivers dies in a crash during the very first race, they discover that what seemed like an uncharacteristic error in judgement may have a more sinister explanation...

Spring, 1909, and Lady Hardcastle, amateur sleuth and all-round eccentric, is enjoying a well-deserved rest. But a week after a trip to the cattle market, Spencer Caradine, a local farmer, turns up dead in the pub, face-down in his beef and mushroom pie. Once again, it is up to Lady Hardcastle and her maid, Florence, to solve the case. Armed with wit and whimsy, not to mention Florence’s mean right hook, the pair set out to discover what really happened and why. Was it poison or just ill luck?

It's Christmas 1909, and for once Lady Hardcastle - respectable gentlewoman, amateur spy - and her lady's maid, Florence Armstrong, are setting sleuthing aside. They are invited to the festivities up at The Grange, as guests of Sir Hector and Lady Farley-Stroud. But barely have corks been popped and parlour games played when a mysterious crime comes to light.

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. 

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...

At the end of her first unsuccessful season out in society, Lady Georgiana has all but given up on attracting a suitable man - until she receives an invitation to a masked Halloween ball at Broxley Manor. Georgie is uncertain why she was invited, until she learns that the royal family intends to marry her off to a foreign prince, one reputed to be mad.

Summer 1933. Fresh from the discovery that she has family living nearby, Kitty Underhay has packed her carpet bag, commandeered a chambermaid and set off on a visit to stately Enderley Hall. She’s looking forward to getting to know her relatives, as well as the assembled group of house guests. But when elderly Nanny Thoms is found dead at the bottom of the stairs after papers of national importance are stolen, Kitty quickly learns that Muffy the dog’s muddy paws on her hemline are the least of her problems. 

A scoundrel lies dying, and he makes his confession; his sins were despicable, and he wants to atone for his wasted life. He bequeaths an invaluable gift to Monks Hood Abbey, an ancient monastery set in a lonely corner of the Yorkshire moors. But sin throws a long shadow and corruption crawls in its shade. Strangers come forward and lay claim to the monks' inheritance.

Who killed Sir Crispin Gibbons? A wedding invitation and news of mischief that could be murder takes Lennox to the Earl of Bloxford's country estate. He, soon, finds himself in a world of purloined artworks, forgeries, and a priceless Bloxford beauty. But who are the Bloxford beauties? And why are they the focal point around which death swirls?

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.

A centuries-old skeleton is discovered in a lonely Scottish Castle. It wears a crown and hides a curse. Swift, the detective friend of Major Heathcliff Lennox, now lives at Braeburn Castle, and it was he who uncovered the skeleton. As ghosts are heard and treasure-seekers appear, the murders begin. Lennox must go to Braeburn and investigate as Halloween draws near.

When London’s finest jazz musicians, the Dizzy Heights, are booked to play the glitzy Midsummer Ball at a country house in Oxfordshire, they expect a weekend filled with flappers and toffs having a roaring good time. But the festivities at Bilverton House take a turn for the worse when the group are stranded by a summer storm. And when a member of the Bilverton family turns up dead in a locked room in an apparent suicide, Skins, Dunn and Ellie realize this is going to be a much tougher gig than they thought.