When the terrorist attack in London during the state funeral of British Prime Minister James Wilson occurred, Mason was in the White House situation room when Vice President Allan Trumbull arrived. When asked how bad the situation was, Mason told Trumbull it was bad and that all communications were compromised. He also told the Vice President that there are satellites, but they came up with nothing. Mason listened as Chairman of the Joint Chiefs of Staff General Edward Clegg send a drone has send visuals of the attack of London and when they saw the devastation of London, he was horrified by the sight of it. Mason was then relieved that Marine One was in the air with President Benjamin Asher aboard. Suddenly, when Marine One was shot by terrorists with Stinger missiles, he was horrified when Marine One crashed into Hyde Park.
Later on, Mason and the others sees a video from the mastermind of the attack, arms dealer and terrorist Aamir Barkawi, revealing his intent to go to war against the Western World over a drone strike against him that killed his daughter. After the message ends, Mason said that the video was on social media and everyone around the world has seen it. He was present when Barkawi made a video call to Trumbull. As everyone was talking how to deal with the situation in London, General Clegg says that every form of communication will likely be in the wrong hand and Mason replied that Mike Banning would know that also. He wonder how Banning would reach out for help as NSA Deputy Director Ray Monroe spotted Banning with Asher and is letting out hand signals. He sees that Banning is taking Asher to the MI6 safe house.
Hours later, President Asher was captured and was about to be executed live with a machete by Kamran Barkawi. As everyone watched in horror, Mason refused to watch. However, President Asher was saved by Mike at the last second, disrupting the live execution.
After London Has Fallen
After the London Siege, D.C Mason continued to serve as White House Chief of Staff. He retired from this position when Asher's presidency ended. Sam Wilcox took his place when Trumbull's presidency began.
Behind the Scenes