Construction workers find the remains of a young man who appears to have been strangled to death more than a year ago, but when his sister is notified, she claims he's been sending her postcards all the while. Rob and Vivienne start to suspect David is hiding something.

When an eight-year-old boy finds his grandfather dead in a pub basement, he tells Rob that he was hit by a man with a baseball bat, but Vivienne doubts his story. Later, Vivienne pressures Rob to report to the Missing Persons Team that he covered for David on the night of Sarah's disappearance.

While the team looks into the murder of a Portuguese au pair who was recently fired from her job, Vivienne and Rob start investigating David on the sly, but he remains a step ahead of them.

The detectives suspect a gangland hit when a father and son are shot execution-style in broad daylight, and worry the violence could escalate; David sees an opportunity to finally apprehend crime kingpin Adrian Cook.

In exchange for turning a blind eye, Adrian Cook gives Rob the name of someone who knows where Sarah is, but that person turns up dead. Believing Sarah may still be alive, David and his team race to her find her.