He wasn't always a killer. At first, he just wanted to talk.

D.C. Charlie Stafford has an odd case on her hands. And it may be her toughest one yet.

A burglar who isn't interested in valuables, the subject of Operation Greystream is a strange but smooth operator. In the dead of the night, gloved and masked, he visits the elderly. He doesn't hurt them and, if they beg, he won't take anything of real value. All he wants is conversation... and they're powerless to refuse him.

But then 87-year-old Florence Briarly is found by her friend, cold to the touch and neatly, too neatly, tucked into bed. And Charlie realises this case has taken a sinister, urgent turn. Now this stealthy burglar has had a taste of murder, it's only a matter of time until he craves it again...