Episode 4

DCI Gene Hunt and his team, DI Alex Drake, DI Ray Carling and DC Chris Skelton, are hot on the tail of a van they believe contains a large amount of heroin. When the Quattro blocks the van's escape route, the team are faced with a woman brandishing a sawn-off shotgun, but bullish Gene shows no fear and heads straight over to take on the female blagger. However, things suddenly take a strange turn when Gene seems to let her escape.

It transpires that the woman is an undercover police officer, and Gene is not happy that an operation is taking place on his patch. DCI Jim Keats is quick to shed some light on the situation; Louise Gardner from Hanfield police station has infiltrated the Staffords, a notorious crime family who Gene shares some history with.

Gene is determined to take over the op, but in no time at all he manages to blow Louise's cover. Jim is not happy, and the situation is made worse when Louise turns up black and blue at CID. With Louise under the protection of Gene and CID, they have to work fast to stop Daniel Stafford getting his latest lot of heroin on to the streets.

As Gene and Alex close in on the Staffords, something is not quite right; some of Louise's reports are missing and it looks as if someone on the inside is bending the rules to help keep the Staffords on the streets.

Meanwhile, the ghostly police constable with the 6-6-20 epaulette number is still haunting Alex, and she's becoming more convinced he's the key to getting home.