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.

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. 

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...

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.

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?

Summer 1911. A scorching heatwave engulfs the quiet town of Littleton Cotterell and brings about an unusually early harvest. The villagers are thrilled, but events quickly turn sour when one of them turns up dead in an apple orchard, stabbed through the heart. Amateur sleuth Lady Hardcastle and her trusty lady’s maid, Flo, suddenly have a juicy case on their hands. Might the mysterious stranger they recently met in the village be to blame?

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...

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. 

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.

Onetime adventurer and now amateur sleuth Lady Eleanor Swift is attending the annual royal regatta with her new pal Tipsy Fitzroy. Tipsy has Eleanor trussed up like a debutante in a new dress, determined to turn her into a proper society lady. Even Eleanor’s favorite companion, Gladstone the bulldog, has a new outfit for the occasion. But the sparkling prize-giving ceremony is interrupted when the devilishly handsome host gulps his glass of champagne on stage and collapses to the floor. The victim is none other than the king’s cousin, Lord Xander Taylor-Howard.

Kitty Underhay is looking forward to a week of long lunches and wedding planning with her husband-to-be, Captain Matthew Bryant. But the plan is derailed when he is called on to collect a former comrade-in-arms, arriving on the 15:50 from Paddington. As the train bearing Simon Travers pulls up to the platform, a piercing scream rises over the screech of its brakes. Travers is dead in his seat, a dagger in his heart. Only a few individuals had access to Travers’s compartment, and Kitty must find out which of these seemingly benign passengers is, in fact, a cross-country killer.

Winter, 1920. Amateur sleuth Lady Eleanor Swift is feeling festive. She is playing host to the entire village at Henley Hall. She’s also purchased perfect presents for each of her household - not forgetting the biggest bone in the butcher’s shop for her partner in crime, Gladstone the bulldog - and is looking forward to celebrating her first English country Christmas. As snowflakes fall, Eleanor is cheering on contestants in the traditional Christmas fun run in the grounds of the hall. But tragedy strikes when one of the runners drops dead at the finish line.

When a prominent family's daughter flees sleepy Sussex to seek a career on the stages of a glittering West End, Harry and Kat are asked to check in on the young woman. But the two of them soon discover that there is a much bigger danger to the woman and her family than mere acting dreams being crushed. Nathaniel Parker, born in 1962, graduated from the London Academy of Music and Dramatic Art and went on to join the Royal Shakespeare Company. His television career began in 1988 when he played Flying Officer 'Flash' Gordon in the LWT mini-series "Piece of Cake".

Lavinia's annual Masked Ball at Mydworth Manor is a highlight of the season, as locals mingle with the great and famous from London. But the lavish party comes to a full stop when one of the guests is found dead down by the lake. It seems it's a clear case of a heart attack. But Harry and Kat suspect that the dead man in a mask was in fact the victim of a clever case of murder. And the killer's work at the party is not yet done... Nathaniel Parker, born in 1962, graduated from the London Academy of Music and Dramatic Art and went on to join the Royal Shakespeare Company.

Late summer 1933. After a quarrel with too-plucky-for-her-own-good amateur sleuth Kitty Underhay, dashing ex-army captain Matthew Bryant is nursing his wounds, and a tumbler of brandy, when there’s a heavy knock at the door and he finds himself arrested for murder. The body of aspiring actress Pearl Bright has been found, strangled with one of Matt’s own bootlaces, and the evidence seems to be stacked against him. The local constabulary might have locked Matt up, but before they can throw away the key, Kitty hears the news and hies to his aid, determined to prove his innocence.