Delta One X-Ray (D1X) was the baseplate for the SAS and the Marines joint team operation in the campaign missions "Ultimatum" and in "All In", as seen in the events of Call of Duty 4: Modern Warfare.

Call of Duty 4: Modern WarfareEdit

When the nuclear missiles in "Ultimatum" were launched, Delta One X-Ray tracked the missiles all the way from the missile launch facility. They provided the assault teams real-time information about the missiles, specifically the countdown to impact, and the progress of the negotiations for the codes with the Russians. Delta One X-Ray also gives the feed by the time the missiles self-destruct.