Here is the (titled "The Enemy Within" or similar, depending on the source):
The victim is identified as Leah Sumner , a 22-year-old care leaver who worked at a local arcade and lived in a hostel. Jenn visits the hostel and finds her room ransacked. The manager admits that Leah owed money to a loan shark named Col "The Fish" Farley .
Jenn and Med raid the farm at dusk. In the barn, they find Leah's phone and a bloodied tarpaulin – but also another girl, Chloe (16) , locked in a root cellar. Chloe whispers that Marcus "got rid of Leah because she was going to talk."
Jenn and DS Med Kharim track Col Farley to a seafront fish and chip shop (his nickname is ironic – he hates fish). Col admits Leah was behind on payments but swears he didn't harm her. He says someone else was following her – a man in a grey BMW.
The episode ends with Jenn getting a call from the hostel. A young woman has just checked in using a fake name: "Erin Townsend" – Jenn's estranged daughter, whom she gave up for adoption 17 years ago and never told anyone about, not even her current family.