The Revenants

Roman Britain - an army is lured into the mountains and slaughtered by a mysterious foe, who attack from out of the mist.

2008 - archaeologist Elsa Chirk discovers an account of the battle and sets off unravelling a mystery dating back thousands of years.

2012 - a mutilated body is found in an alley in Manchester. DCI Owain Davis begins an investigation which will bring him on a collision course with Elsa - and the mystery she is unravelling