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.

When she's not digging up bones or other ancient objects, Ruth Galloway lectures at the University of North Norfolk. She lives happily alone in a remote place called Saltmarsh overlooking the North Sea and, for company; she has her cats Flint and Sparky, and Radio 4. When a child's bones are found in the marshes near an ancient site that Ruth worked on ten years earlier, Ruth is asked to date them.

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...

Selchester Castle in 1953 sits quiet and near-empty, its corridors echoing with glories of the past. Or so it seems to intelligence officer Hugo Hawksworth, wounded on a secret mission and now reluctantly assuming an altogether less perilous role at Selchester.

When a young boy discovers the body of a woman beneath a thick sheet of ice in a South London park, Detective Erika Foster is called in to lead the murder investigation. The victim, a beautiful young socialite, appeared to have the perfect life. Yet when Erika begins to dig deeper, she starts to connect the dots between the murder and the killings of three prostitutes, all found strangled, hands bound, and dumped in water around London.