Episode #1.6

Plot:

The group is forced to leave their country house headquarters when Sarah betrays the fact that Anya is a doctor and Tom kills one of Samantha's men. They relocate to the city where Naj gets lost and is eventually found,having been taken in by Craig, a sort of Fagin figure who, with his partner June, gives boys a home in exchange for what they can scavenge. The other survivors take Naj from Craig but are ultimately tracked down by Samantha's people in a rooftop car park where Greg is shot and Abby is captured and driven away.