Deep below the hills of the Buckinghamshire countryside, the infamous Hellfire Caves house a pleasure palace for the idle rich – a secret society steeped in satanism, opium and debauchery of the highest order. When the club’s warden, Antony Pennington, is brutally murdered, his bastard sister, Dora, must follow the clues to decode who the killer is, aided by an unexpected ally – ex-Army officer, former opium addict and son of a Viscount, Dr Jacob Sandys.

Investigative duo, Dora Fitz-Pennington and Dr Jacob Sandys, have escaped London and headed north to the Lakes, both needing time away from danger after their two most recent cases. Death, unfortunately, hasn’t got the message that it isn’t welcome to join them. Now, as William Wordsworth’s opus goes missing, and disappearances and a murder follow in quick succession, Dora and Jacob are forced to abandon their holiday and use their unique skills to track down a reckless killer intent on destroying the Romantic poets and all they stand for…

Miss Penelope Monckton, just returned from nursing with Florence Nightingale's in Crimea, has come to the country estate of one of the most scandalous men in England, Lord Rickarby—nicknamed Rakerby—to collect a bequest from his late wife, her childhood friend Millie. But something about Millie's death doesn't sit right with Penny. A celebrated painter, Joss, Lord Rickarby, knows Miss Penelope Monckton only from the letters she sent to his late wife during her time nursing in a war zone.

Sir Huxley, famed gentleman inspector and Beatrice’s former crush, is still considered the real investigator in London, so the only cases left for Beatrice and Drake are lost pets and spectacles. Not that Beatrice has much time for crime-solving, anyways, as her mother still expects her to find an eligible (rich) husband to protect their family from destitution. Beatrice is struggling to balance all the demands on her and begins to wonder if she can become a true detective in a city that feels full of false promises.

Lady Hannah Simmons is a quintessential wallflower, unassuming, dowdy yet ignored by most. But underneath her plain exterior, Hannah is hiding a thrilling secret! Unbeknownst to the rest of the ton, she is Queen Victoria’s leading femme fatale, slipping unnoticed through the streets of London and listening to scandalous whispers from lords and ladies. But with daggers in her stockings and pistols in her pockets, Hannah's mission is to apprehend a deadly killer.