Ruth finally tracks down her sister and flashbacks reveal the circumstances behind the murders that saw her jailed for 15 years. Steve's increasingly manic quest for revenge leads him to the Belcombes' home, where he takes a hostage.

As Lucy recovers, her parents decide to respond to John's letter and meet up with Lucy's real sister. Izzy learns the truth about Ruth, and Steve plots his revenge.

Drastic consequences arise for three seemingly unrelated families following the release of Ruth Slater, after serving 15 years in prison for murdering two policemen.