While tensions between the U.S. and North Korea are in heightened state of alert, Major Garcia, a Wyoming missile silo commander, is under pressure to perform despite computer hardware and software issues. And Frank is sent to Washington to answer to the Backstep Panel for a drunken stunt.
When an F-16 strays into a no-fly zone, the North Koreans shoot it down. The U.S. retaliates by destroying the SAM site and a North Korean general escalates the issue by firing an ICBM, forcing the U.S. to escalate to DefCon Two, sending EAM's (Emergency Action Messages) to all silos.
After the North Korea assures the President that the ICBM is not armed and will fall harmlessly into the sea, the President orders the military back to DefCon Four. Abort EAM's are sent out to all silos and all except the one in Wyoming stand down. Instead of standing down, the silo launches its ICBM and North Korea retaliates with a nuclear strike that destroys the silo and half of the Western U.S.
At Area 51, an EMP (electromagnetic pulse) neutralizes most of the computers onsite but Owsley manages to get them back online, albeit in a reduced capacity. Since Frank is still off-site, Donovan is picked to pilot the sphere. However, insufficient reactor power prevents a successful Backstep and Donovan is severely injured. Parker returns and six days later power has been restored and another Backstep is barely successful. Frank arrives at the Wyoming silo just after they received the EAM alert.
When the abort EAM is sent out, the silo's hardware deletes the message before it can be read and Major Garcia proceeds as if it is a genuine alert. He ignores Frank's warning and has him arrested while proceeding to launch. Colonel Beekman helps Frank and he contacts Bradley to request an air strike against the silo. When the Backstep Panel turns down Frank's request, Bradley launches a F-117 bomber from Groom Lake.
Frank convinces the Comm Officer Lt. Rogers to get the receiver fixed. Frank and Beekman delay the missile launch but when the air strike hits they have to go directly to the silo and abort the missile. Lt Rogers gets the receiver fixed and the abort EAM comes through in the nick of time and they abort the launch.
Due to his exemplary work in Wyoming, the Panel relents and just gives Frank a two-day suspension. Major Garcia is cleared of all charges. Owsley notes that Olga went to bat for Frank with the Panel.