The National Security Agency (NSA) is a U.S. intelligence agency responsible for the production and management of signals intelligence and information assurance for the United States government. They assist the Federal Bureau of Investigation in helping track down cyber-terrorists responsible for the Fire Sale.
At the FBI mobile command center, Summer, along with Parry, arrived. He reveals that the White House made a call to help about the systematic attack against the United States. They asked for some workspace for to their people. Summer and Parry were present when the terrorists took control of the broadcast stations and we're horrified when the U.S. Capitol was "blown up". Later at night, Summer and Parry bring all of their agents and functioning hardware they got over to the FBI at Bowman's request. Summer and Parry we're silently horrified after John McClane of the NYPD revealed the identity of Thomas Gabriel, knowing what he's planning to do.
Afterwards, Summer came to Parry at his request. Parry tells him the alarms are going off in Woodlawn and suspects it was Gabriel. Bowman overheard them and demands to know what it is. Both Parry and Summer reluctantly reveal that Woodlawn is a secured facility underneath the Social Security Administration which contains back-up servers that stores financial data in case of total network attacks, like the one Gabriel orchestrated. Summer states that if Gabriel get into the systems, he can download the data and use it to siphon billions. When an angry Bowman asked how Gabriel knew about the financial servers since he never knew the existence of it, Summer sighed heavily as Parry states that Gabriel designed the system during his DOD tenure, which angers Bowman even more for knowing all this.
Both Summer and Parry are not seen again after McClane defeats Gabriel and his henchmen.