Gene and the gang go undercover...

As DCI Gene Hunt and the team bust a major drug deal, Alex finds a scared young girl, Nina. At the station, prostitute Trixie claims she's been raped - but Gene doubts her until she reveals a wound. It's identical to one found on a choirgirl who was killed before Alex's arrival, so Gene kicks off the hunt for a serial killer.

Gene's certain the attacker will be on the boat where Trixie was attacked. But it's owned by a friend of the Commissioner, so Gene, Alex, Ray and Chris attend an onboard fancy-dress party dressed as Clint Eastwood, Catwoman, James Bond and Superman to avoid getting spotted.

Despite their cover being blown, the suspect is arrested - but with Trixie being a woman of unreliable character, and the only witness, there's little chance of making the evidence stick. But when Ray reveals his softer side, Nina breaks her silence, providing evidence that could cement the case...