The relief investigate when an unidentified five-year-old girl turns up in St. Hugh's hospital having accidentally ingested crack cocaine. With very little to go on, the search becomes underway to find her mother, but it's not long before Boyden realizes the girl's mother is none other than his own tearaway daughter, Amy. The case takes on a different dimension for Best when he interviews a witness and discovers that Klein was also in the taxi that dropped the little girl off at the hospital. Back at the station, a thief is at large, and Tait is in the frame when Glaze's phone is found in his locker, while Nixon faces facts when her trouble-making teenage daughter Abi is brought in for being drunk and disorderly.