The Downton Abbey meets Knives Out in this new exciting series of detective novels, where an unlikely duo of investigators searches for a murderer in a mansion that has been hermetically sealed to protect against total destruction.

Cornwall, 1910. On a remote island defined by the tides, Lord Tait Hall is feverishly preparing for the disaster he believes will be caused by the passing of Halley's comet. The manor must be sealed from top to bottom – every window, chimney, and lock must be secured before night falls. But what the arrogant and corrupt viscount has not considered is the danger lurking within Tait Hall... The next morning, he will be found dead in his sealed office, murdered with his ancestors' crossbow.

Everyone's suspicions point to Steven Pike, the new servant. Imprisoned in the past for a crime he didn't commit, he is the wrong person in the wrong place at the wrong time. His unlikely ally? Miss Desima Stokingham, the outspoken, sharp-witted, octogenarian matriarch of the family. Fearless and unconventional, she enjoys mysteries and puzzles, and a murder offers her exactly the adventure she was seeking.

This mismatched duo must explore secret passages, dig up old scandals, and confront the spreading terror to uncover the killer before it's too late...