Hidden on the Fens

Detective Joseph Easter's daughter discovers a cottage hidden in some trees on a large fenland farm. Someone has been living there.
The farm-owner's wife has been receiving sinister pagan artifacts, including a witch's knife. Are they some sort of warning or message?
Joseph and his daughter search the cottage and find an old satchel. Inside are photos of a beautiful girl, Jennifer Cowley. She went missing fifteen years ago. She'd been stalked by a young man, who was convicted of her murder, even though her body was never found.
WHEN DI NIKKI GALENA EXAMINES THE COTTAGE, SHE FINDS SOMETHING FAR WORSE.
And in the satchel is a more recent photo of a girl who looks just like Jennifer.
THE MAN WHO KILLED JENNIFER IS RECENTLY OUT OF PRISON. HAS HE STRUCK AGAIN?
At the same time, DC Cat Cullen and Dave Harris are trying to get evidence against a man who preys on widowed older women. Vernon Deacon is seemingly a pillar of society, with very influential friends. But his victims aren't believed, so their job is not easy.