A stranger is just a killer you haven’t met yet… The Sunday Times bestseller returns with the next big thing to hit the shelves. If you haven’t discovered Paul Finch yet, this book will have you hooked.

Unknown, alone, and fearing for your life: as PC Lucy Clayburn is about to find out, going undercover is the most dangerous work there is.

But, on the trail of a prolific female serial killer, there's no other option — and these murders are as brutal as they come. Lucy must step into the line of fire — a stranger in a criminal underworld that butchers anyone who crosses the line.

And, unknown to Lucy, she's already treading it…