S5·E1 Hooked

Disgraced Chappel has been transferred to a desk job following the events of the operation into the paedophile ring, and Vickers has been drafted in to head-up the vice squad as his replacement. When Chappel discovers that Hutchins has disappeared during an undercover operation into a pornographer, he becomes obsessed with finding her.

Using his informants, Chappel manages to locate Hutchins, only to see her destroying herself with a powerful addiction to crack cocaine. Risking everything to save her, and under a watchful eye from Vickers, Chappel takes Hutchins to a safe house. But when he discovers that the pornographer raped her, Chappel finds himself up on a murder charge.