A drug overdose brings the Blackthorn team into the world of Belfast’s seemingly innocent elite. Grace considers her failings when she is confronted by a face from her past.

A car crash has traumatic consequences for Aisling, while the fallout creates a deadly situation for the section. Grace turns to child protection to try and help Lindsay.

Grace and Shane push boundaries for Lindsay’s sake as a threat closes in. Aisling and Tommy respond to a call out where things are not as they seem, with unexpected consequences.

Grace offers up a secret about her own past in an attempt to break through to Lindsay. Aisling’s erratic behaviour forces Tommy to make a heartbreaking decision.

Grace and Sean bring in George for questioning, leading Morgan to take drastic measures to silence him. Shane faces an unexpected situation on a routine callout.