The next agent on the Soviet list, Tom Mallory, is a brutal man currently in prison for assault. Without his freedom, he can’t perform his task and bring MI5 one step closer to thwarting Operation Glass – leaving Daddy with a terrible choice. Joe, haunted by events in his past, continues to struggle with his lover’s killer’s role in the plot. But when it’s revealed that a possible nuclear strike is imminent, Joe makes a deadly decision to stop the information from falling into enemy hands.

The show’s own verdict is on its page.