DSI Stella Gibson's worst fears are realised as Spector's murder spree in Belfast continues and she faces very real consequences after a reckless decision.

When Eastwood's investigation into Olson's murder throws open some uncomfortable truths for Burns, Gibson comes under increased pressure in her hunt for Belfast's killer.

The killer's latest attack gives Gibson renewed impetus. As the net appears to be closing in, Spector makes a dramatic confession and a decision that binds his fate to Gibson.