Saturday, October 18 at 8:30pm

After the death of their colleague PC Emma Keane, the Sun Hill team is dealing with another bomb threat, and they're no closer to finding the bomber. DCI Jack Meadows and CO15's DI Karen Lacy (Liz May Brice) now suspect it's the work of one person - someone targeting 'the four evils of the internet', but the only other clue they have is a man with a motorbike helmet spotted on CCTV at several of the sites.

As they desperately search for clues, DC Grace Dasari (Amita Dhiri) conducts an interview with the men targeted in the earlier incidents, in an effort to find a common link, but it's not until they've left the station that they realise they have let the bomber go. As the other uniformed officers attend PC Keane's funeral service, Sgt Stone excuses himself to help CID, but ends up putting his own life on the line...