The Seventh Girl (Detective Kat Ballantyne, #1) by Andy Maslen

She thought he was gone. She was wrong.

Fifteen years ago a serial killer was on a rampage murdering young women in Middlehampton. Then the killings stopped, and the murderer evaded the police.

So when the body of another young woman is found bearing the twisted killer’s unique hallmark—the overpowering stench of lavender and an origami heart—DS Kat Ballantyne knows this can only mean one thing: the killer is back.

For Kat, whose best friend was the killer’s last victim all those years ago, this is deeply personal. She’ll stop at nothing to prevent more women dying and bring her friend’s murderer to justice. But the scent has gone cold once before. Kat will need all the help she can get in her investigation as she hunts down leads and encounters dead ends and horrifying twists.

With time running out, can she finally crack the case and put a stop to the killings—or will she be the next victim?