As the nuclear mushroom cloud grows larger, threatening the further evacuation of Los Angeles, Jack's brother Graem reveals the connection between his company and Darren McCarthy, the man hired by Abu Fayed to reconfigure the nuclear weapons. Meanwhile, heightened security measures put in place by Tom Lennox puts pressure on CTU Agents, as well as Karen Hayes, who is forced by past events to tender her resignation to President Palmer. Jack finds his father and Graem's motives are made a little bit clearer.