It’s the year 2022. Dani Peterson has been walking in the west of Ireland, conducting historical research for her dissertation. But when she seeks shelter from a storm in Aideen O’Brien’s car, she gets more history than she bargained for. Aideen is a Time Link, with secret access to time travel technology. She sends Dani to 1978 to meet a younger version of herself. The two fall in love and Dani joins Aideen in her work. Their boss is a man from 2253 named Charles Burke, who says his mission is to save the future.

It’s Mallory Atkinson’s first Christmas in Scotland. Victorian Scotland, that is. Also, as the twenty-first-century detective learns, Christmas really isn’t a thing in Victorian Scotland. It’s all about Hogmanay. But her boss, Dr. Duncan Gray, treats her to an early gift of tickets to the event of the season: a Charles Dickens reading. There, they bump into Lady Inglis—the lovely widow who has sent Gray sexy letters trying to entice him back to her bed.

May 20, 2019: Homicide detective Mallory is in Edinburgh to be with her dying grandmother. While out on a jog one evening, Mallory hears a woman in distress. She’s drawn to an alley, where she is attacked and loses consciousness. May 20, 1869: Housemaid Catriona Thomson had been enjoying a half-day off, only to be discovered that night in a lane, where she’d been strangled and left for dead. When Mallory wakes up in Catriona's body in 1869, she must put aside her shock and adjust quickly to the reality.

Weaving back through time, the secret society of eccentric anachronists ensures the best possible future for humanity, making subtle adjustments to the past—saving us from oblivion. Every alteration is carefully calculated, and nothing is left to chance. Until the day Joshua Jones, a teenage thief, breaks into one of their station houses and finds himself transported back to 1944—where he accidentally changes the outcome of WW2.

In the spring of 1685, Lord Hugo Everly, ardent supporter of the Protestant upstart the Duke of Monmouth, vanishes without a trace just before the Monmouth Rebellion, leaving future generations forever baffled as to what might have become of him. In 2013, while visiting Everly Manor as part of her job as a location scout for a film production company, Neve Ashley stumbles onto a secret passage that leads her into the 17th century and straight into the path of the ill-fated lord.