When a Friday evening trip out in the car ends in a fatal crash, the driver refuses to accept his driving is to blame. The collision team must find the evidence to prove the real story of the night.

When a head-on crash leaves a grandfather dead, Chris discovers the answers could lie in electronic data within the car. As his mission to access it begins, he unearths an intriguing story of what really led up to the crash.

The collision team are called in to investigate a high-speed crash on the M4 which closes the motorway in both directions. With a driver under arrest and offering few clues, the answers could lie with a silent witness.