Contains spoilers for this episode and earlier episodes.
Tommy prepares the robbery while trying to keep Arthur available for one more criminal operation. Linda negotiates directly with him over Arthur's involvement and their hopes for a different life in California. She refuses to treat Tommy's wishes as automatic orders. Her plans for Arthur and the child force Tommy to bargain for help he once expected simply because they were brothers.
Polly goes to confession after drinking and reveals that Tommy intends to kill a priest. The information reaches Hughes. Tommy is seized and brutally beaten, then told that the leak to the Soviets was part of the Economic League's own scheme. Hughes threatens to take Charlie unless Tommy withdraws his accusation and apologises in front of the Russians. Injured and under pressure, Tommy performs the humiliating act of contrition demanded of him.
Rather than accept the conspiracy's purpose, Tommy asks Ada to arrange a meeting with a Soviet representative. He explains that the robbery is bait intended to provoke Soviet violence on British soil and rupture diplomatic relations. His family would become expendable casualties if the train were attacked. After delivering the warning, his injuries overwhelm him. He tells Ada that he has a fractured skull and internal bleeding and asks her to drive him to hospital as his sight begins to fail.