Nikki comes face to face with CEO Simon Laing when it becomes apparent that the motive for the murders may have been blackmail.

When the team find that the hospital computer database has been hacked, Clarissa and Max follow the forensic clues to a teenage hacker called Splinter.

However the danger grows much closer to home when Nikki receives a threatening text with a picture of Thomas's daughter Rosie.

Nikki is still in shock as the team arrive at Matt's residence but insists on working at the Lyell, determined to help. When analysing crime scene photos and the positions of the victims' bodies, Nikki realises there is a pattern. Together, the team uncover a secret that has been held by those at the very top of the US government.