The season finale centers on the fallout of the Russian plot to stage a "revenge" mission against MI5.
River Cartwright (Jack Lowden) narrowly avoids a disaster after misidentifying a threat at the Glasshouse, while Louisa Guy (Rosalind Eleazar) deals with the emotional and physical aftermath of Min Harper's murder earlier in the season. Critical Reception
Jackson Lamb tracks Katinsky to a remote location. In their final confrontation, Katinsky reveals his personal vendetta: he blames Lamb for the death of his former colleague. Rather than being captured, Katinsky chooses to take his own life after Lamb exposes the futility of his mission.
Gary Oldman’s portrayal of Jackson Lamb continued to be the series' anchor, noted for his "sarcastic attitude and heavy presence".
