Agent One was part of a two-man Splinter Cell team with Agent Two as they first appeared together in the co-op campaign mode of Splinter Cell: Chaos Theory where they operated during the events of the Information Warfare Attacks and East Asian Crisis in 2007. He appeared again with Agent Two in the co-op campaign mode in Version 2 of Splinter Cell: Double Agent assisting Sam Fisher during the events of the JBA Crisis in 2008.
Agent One and Agent Two began advanced Splinter Cell team-training shortly until the Korean conflict started. As demonstrated in the field some of Agent One's training may have involved foreign languages, knife combat, advanced co-op stealth tactics, restraining techniques, and possibly even emergency first aide among numerous other skills. Uncharacteristically, they are given similar weapons as Sam Fisher, boosting them to lethal status. After completion of the Splinter Cell team-training program, and the Panama mission, they were designated as the first official-unofficial Splinter Cell team. This unique covert ground team performed the latest in co-op stealth tactics in the field and greatly excelled. They proved the efficiency of deploying teams of two into the field to accomplish covert operations. Their most notable covert operation was the Three-Block War of the East Asian Crisis in 2007.
Shortly after completing Splinter Cell team-training program, though they were still in training when they were deployed, as they had not made the grade yet as official-unofficial Splinter Cells. The Splinter Cell team was inserted into Panama to recon other deals by Señor Segundo Ruiz De Medeiros, Vice President of MCAS Banco de Panama who made deals between Displace International and Hugo Lacerda as well as tying up the loose ends and clues that Fisher picked up from Lacerda. After interrogating De Medeiros and sifting through all available records, they learned that he had made deals other than aiding Hugo Lacerda, and had also dealt with a North Korean weapons scientist named Jong Pom-Chu.
After their Panama mission was skillfully completed, the now official-unofficial Splinter Cell team were sent into war-torn Seoul. Where they were tasked with destroying any anti-air weapon vehicles and capturing and securing Jong. Unexpectedly, he was relocated during the mission, and Fisher was ordered to interrogate a North Korean Special Forces soldier to find out where or the mission would have ended in failure. Upon receiving this vital intelligence, the team dismissed the idea that he is another Splinter Cell, as they believed they were the first. The team eventually tracked down, captured, and evacuated Jong via disappearance cargo truck parked out front the cyber cafe, after disabling his escape boat. They discover that Jong had been developing a chemical weapon and are sent to a silo in North Korea to locate a strain of the virus and create a vaccine.
The Korean conflict was over by then, but they learned that North Korean Colonel Kim had refused to lay down arms and led a rogue faction of the army to plant bombs within New York. The two agents head to the train station and disable the bomb. They head back to North Korean soil to learn that Kim had the ability to strike a final time, at the United Nations (UN) Headquarters in New York. The team goes to the UN HQ in New York, where they kill Kim and disable the last bomb.
Shortly after Fisher was pulled out, the spies were sent in to complete his mission by blowing up the plant. Following that, the spies go to Ellsworth Penitentiary to start a riot, providing a distraction to allow Fisher and Jamie Washington to escape. Thanks to intelligence provided by Fisher, the spies were able to sabotage the chemical bunker in Kinshasa owned by Tafkir and Massoud, as well as gather valuable intelligence. The last mission happened in conjunction with Fisher taking down the JBA. Under the command of Assistant Director Williams, The Splinter Cell team sabotaged multiple Red Mercury bombs on the tanker (hijacked by Fisher during his mission in Russia) heading for Los Angeles Harbor (see Notes).