Katie always prided herself on being a responsible big sister - until she left her brother Chris alone for one selfish afternoon, and everything fell apart. Although he survived the attack, the scars ran deep - physical, and emotional. Now they're adults, and they haven't spoken in years.

Then she gets a call - from a detective. A body has been found in a sprawling mansion - one that remains half-ruined by a decades-old fire. Chris is the prime suspect.

Katie knows this might be her last, best chance to save her brother. But she doesn't realise that this isn't the first murder - and so she doesn't know how much danger she's in...