Another day another find for dog trainer Cory Pratt's cadaver dogs Alice and Rex. This time a mass grave with three bodies and a second single grave over three decades old. A cold case that Cory's sibling and Chicago Police detective Crystal has to solve fast as the killer of the four men is still out there.

While the identities of the men are determined one by one, the bodies are linked to an infamous crime which remains unsolved to this day. And with the killer trying to cover their tracks, other dangerous and lethal individuals start getting involved . . .

Figuring out what happened all those years ago while trying to minimise the current body count, Cory, Crystal and the dogs are hot on the heels of the killer. But their involvement puts them right on their list and in more danger than they bargained for.

For fans of action-packed K-9 mystery series, such as Margaret Mizushima's Timber Creek K-9 mystery, Paula Munier's Mercy Carr mystery and Susan Furlong's Bone Gap Travellers mystery: "A mighty impressive thriller" (Booklist)