Mercy Watts and her grandad, Ace, survived the Sturgis Motorcycle Rally and are racing home ahead of a stalker whose plans for the Watts clan remain unknown.
But they’re too slow and what Mercy finds at home spins her in a new and darker direction, taking her back out to her least favorite place on Earth, Hunt Hospital for the Criminally Insane. Soon she’s sucking up to a serial killer and going toe-to-toe with a rogue rapist.
Mercy wants to hand this case off to her father, Tommy Watts, but the great detective is missing in action, just when his family needs him most. So it’s up Mercy and her nerd crew and they’re going to have to power through, battling the cops, the FBI, and a killer who has connections and no scruples.
Since killing a man in New Orleans Mercy's kept her head down. With diet, exercise, and work, she thinks she can keep wolves and memories at bay. She's wrong. The Costilla gang wants revenge and Mercy will pay with her life if they can get to her.
Her father, Tommy Watts, decides to send her to an isolated castle with an ominous past owned by a pair of innkeepers with no past at all. Tommy's solution is simple. He'll take care of the Costillas while Mercy's tucked away out of sight in the countryside. If only he hadn't sent her cousins with her, three girls with issues and a lot of duct tape. Dad said Mercy would be safe there, but she's the only one. The castle is hosting a baseball camp and the competition is about to get fierce and deadly.
The Fibonacci family saved Mercy Watts’ life and now she owes them a favor. Calpurnia Fibonacci calls on Mercy to make good. When you’re dealing with a powerful mafia family, refusing isn’t an option. So Mercy travels to Paris, home of the Louvre, catacombs, and secrets, to search for the identity of a woman glimpsed for just a moment on the fashionable Rue Cler and some answers to a few family mysteries of her own. To make matters worse, Chuck and Aaron tag along and they have agendas of their own. With the mafia and the shadowy Klinefeld Group involved, finding the wife of Riley will be much more dangerous than she ever expected.
Mercy Watts is barely back in St. Louis before her hometown suffers the worst crime in a century, a mass murder at an Italian restaurant. This has nothing to do with Mercy and she’s determined to keep it that way. No news. No gossip. No evidence. No bodies. Mercy doesn’t want to know. But there are some things she can’t avoid, her family and her friends.
Officer Joey Ameche has a marker and he’s calling it in, much to Mercy’s dismay. His sister needs help and Mercy’s expected to pay Joey back by clearing her from any involvement in the Tulio murders. That mass murder leads Mercy to her smallest criminal yet, a tiny bacteria with huge potential for murder. She traces that nasty bugger to New Orleans, her mother’s hometown, where the crimes keep adding up and the lies are thicker than Nana’s gumbo.