Never underestimate a librarian. Comfortably padded and in her middle years, Shona McMonagle may look bookish and harmless, but her education at the Marcia Blaine School for Girls has left her with a deadly expertise in everything from martial arts to quantum physics. It has also left her with a bone-deep loathing for The Prime of Miss Jean Brodie, that scurrilous novel that spread scandalous untruths about the finest educational institution in Edinburgh. Her skills, her deceptively mild appearance, and her passionate loyalty make Shona the perfect recruit for a new and interesting project: Time-travel to Tzarist Russia, prevent a gross miscarriage of romance, and – in any spare time – see to it that only the right people get murdered. It's a big job, but no task is too daunting for a Head Girl from Miss Blaine's.

A resourceful middle-aged Scottish librarian travels back in time to stop Macbeth and his wife from killing Duncan while avoiding three dangerous witches.  Shona McMonagle is your ordinary, garden-variety librarian: comfortably padded, in her middle years, expert in various arcane martial arts. She also has an impressive knack for time travel (“impressive” may be overstating things: her first two forays—revolutionary Russia, 19th-century France—went less than smoothly).   Her latest mission? Head to 11th-century Scotland, cozy up to Macbeth and Lady M, prevent them from murdering Duncan. In the ordinary course of things, this would be a doddle. But then there are the witches, who prove remarkably quick to take offense. And the business of being turned into a mouse. And the fact that the mission is in truth threefold. One, keep Duncan alive and kicking; two, correct the historical record and lay bare the ludicrous lies introduced...

The intrepid librarian Shona McMonagle, erstwhile Marcia Blaine Academy prefect and an accomplished linguist and martial artist, finds herself in an isolated French mountain village, Sans-Soleil, which has no sunlight because of its topography. It's reeling from a spate of unexplained deaths, and Shona has once again travelled back in time to help out.Forging an uneasy alliance with newly widowed Madeleine, Shona is soon drawn into a full-blown vampire hunt, involving several notable villagers, the world-renowned soprano Mary Garden – and even Count Dracula himself. Will Shona solve the mystery, secure justice for the murder victims and make it through a deathly denouement in the hall of mirrors to return to present-day Morningside Library?