Part 1 (S03E01)

DCI Red Metcalfe's exceptional skill in understanding twisted criminals faces its greatest challenge when he comes face-to-face with a long-time foe, Pace Tierney, whom he believed he had locked away for good. The investigation into prison violence, led by DS Kate Beauchamp, quickly spirals into chaos as inmates, spearheaded by Tierney, initiate a violent uprising and seize hostages, plunging everyone into a harrowing situation.