It’s the summer of 1963 and Gabriella Farnsworth is a newly-minted London traffic warden. She’s used to temper tantrums, swearing, and threats, but finding a dead body is an entirely new low. She isn’t interested in getting more involved than she already is in the investigation into the man she found’s death, but when, a few days later, she stumbles over a second body lying feet away from where she found the first, she can’t avoid it. She knows the streets of her route, knows the people on them, but she is absolutely astonished when New Scotland Yard discovers the art gallery near where she found the bodies is a front for mixing up a new psychedelic drug. Suddenly, the reason for the killings starts to make sense, but what neither she nor the New Scotland Yard detective assigned to the case understand is that the killer’s agenda is more complex than a drug turf war, and by the time Gabriella works it out, it just might be too late . . .

It’s autumn, 1963, and there’s a dark cloud hanging over London. Literally. The thick, impenetrable smog is the perfect cover for a killer who’s stalking the streets, not that traffic warden, Gabriella Farnsworth, knows that when she’s approached by three young boys who say they’ve found a body. When her boyfriend, Detective Sergeant James Archer, gets assigned the case, he begins to build a picture of the killer’s patterns and becomes increasingly nervous every time the smog settles over the city. Especially when bodies are found once the mist clears. Gabriella’s diverse contacts on the street provide vital information that help James understand that these murders are not the start of a killing spree, they are a continuation of one that came before. They’ll have to go back to what happened during the Blitz, to another time when London was shrouded in darkness, to find the clues to catch the man who’s returned to kill again. James and Gabriella know that they have to solve the mystery before the next fog descends, because when it does, the killer will strike again.