A woman and her teenage daughter are found murdered in their South London home. The girl's throat has been cut. Her mother stabbed to death.

When DC Maeve Kerrigan arrives at the scene, her first thought is that this is a domestic dispute gone bad.
But the husband - found bloody and unconscious in an upstairs room - insists he's the third victim not the killer.

With Maeve's only witness refusing to talk, how will she unravel the truth?