New recruit DS Max Carter joins the Sun Hill team from CO19 to investigate a tip-off about an armed cash-in-transit robbery, only to find partner DC Perkins drowning his sorrows after the informant is killed for his pains. PCs Gayle and Armstrong arrest two girls for failing to pay their cab fare, and a catastrophic train of events is unleashed when it emerges they were carrying a deadly cargo smuggled in from Ghana - and their boyfriends want it back.