Ben's response to a state of graffiti attacks on Mt Thomas signs and icons is to suggest a policy of zero tolerance of all minor offences. Ben and Jo certainly do not see eye to eye on zero tolerance and its effectiveness, and when they become involved with a group of young street kids squatting in a house, their differing approaches are put to the test, and their working relationship becomes strained. Jo seems to be proven right when first the squat the kids live in is bulldozed, and then one of them narrowly escapes injury in a charity bin fire, but Ben stands his ground. Ben and Jo must put aside their personal differences to discover that the most useful part of zero tolerance is tolerance itself.