Under the marsh

Twelve years ago DI Monica Kennedy caught the notorious serial killer Pauline Tosh, imprisoning her for life. When Tosh asks Monica to visit her at the remote Highlands Carselang prison, the detective thinks she's playing games. But then Tosh hands her a hand-drawn map with a cross marking the desolate marsh lands near Inverness and Monica can't ignore it - she was always convinced there were more victims out there. And when a body is discovered it looks like they've found a new name from Tosh's kill list. But things are never that simple.