When a climate activist is left for dead after a hit-and-run, he uses his dying words to name his killer - a serving police officer. With the country divided, will defence solicitor Sam Malik take on the trial of the decade?

As Southgate builds his case against Justin, attention turns to the D4 police chat group. With phones wiped and fellow officers saying nothing, could D4 hold the key evidence?

The trial begins, with protests outside the courthouse. As the prosecution lay out their case, Sam picks holes in their evidence. But can he control a dangerously unstable Justin?

As the trial resumes after Justin’s shocking outburst, he finally takes to the stand and the question is put to the jury: is Justin Mitchell mad or bad? With Felix pointing to a bigger picture and the public baying for blood, Sam tries desperately to save his client. What choice will the jury make?