Single Player
Taking place three years after the events of Splinter Cell: Double Agent, former Navy SEAL Victor Coste is held in a Black Arrow facility interrogation room as he is interviewed by an unidentified group of men, recalling events in the past tense.
After having disappeared, Sam Fisher is remotely located by former Third Echelon colleague Anna "Grim" Grimsdóttír in a marketplace situated Valetta, Malta. He is warned that a group of hitmen have located him. Sam dispatches them and interrogates the leader, learning that drug runner Andriy Kobin was responsible for the death of his daughter, Sarah. Sam learns that Kobin is present in his mansion, a re-purposed museum. Upon infiltrating the mansion, Sam interrogates Kobin and learns that the situation was "bigger than his daughter," prior to being captured by Third Echelon agents.
Sam is relocated to Price Airfield in Virginia, where Grim reveals that she is working with President Caldwell as a mole for Third Echelon, and that she needs his help with investigating a PMC named Black Arrow. A reluctant Sam refuses to help her, but relents after being told that Sarah is alive, and that she would prove it to him during the course of the investigation. Grim facilitates Sam's escape from the airfield by providing him weapons and access to her car. At Grim's request, Sam beats her to make it appear that he escaped by force, to prevent Grim's cover from being blown. After this point, Sam calls in his former squadmate for assistance in the investigation, in part of Victor having rescued him during the events of Operation Desert Storm. Sam meets with Victor at a county fair in the Washington Monument in Washington D.C., receives some equipment, and learns that White Box Technologies, a research-and-division company specializing in EMPs, hired Black Arrow for corporate security, which is considered to be out of character as Black Arrow does not provide it.
Sam heads to White Box Technologies and witnesses multiple scientists having been murdered by Third Echelon director Tom Reed and Black Arrow operatives. Fisher saves one of the scientists and learns that Lucius Galliard hired Black Arrow to provide security, and that Robertson has been collecting and disposing of experimental data with EMP countermeasures. Sam reaches Robertson's office and downloads the data for Grim's analysts to study. He later triggers an EMP to prevent Black Arrow's tracing of the download in order to maintain Grimsdottir's cover.
Sam is later directed to the Lincoln Memorial under orders from both President Caldwell and Grim, infiltrating the area to record a conversation between Reed and Galliard. Sam later interrogates Galliard, only for the latter to get assassinated by a gunman. Sam pursues the gunman, only for the gunman to get killed by a car bomb. Sam is later drawn into a confrontation with Third Echelon agents until he is extracted by Secret Service.
Sam infiltrates the Third Echelon headquarters to recover equipment and retrieve information from Reed's office. Instead of finding Reed, Sam re-encounters Kobin and interrogates him again. Sam learns that Reed was working with Megiddo to smuggle EMP technology into the United States, and use that technology to facilitate Caldwell's assassination and have the Vice President take over the position since he was "in Megiddo's pocket." As a result of facilitating the assassination, Reed would then be promoted within the higher ranks of the government and be considered a hero. Kobin later reveals that he never knew anything about Sarah and only provided a false body to stage her death, urging him to ask Grim as she knew the whole story. Sam confronts Grim with the information he learned, and is urged to view a video recording Lambert made shortly before his death at the end of the previous game. Sam learns that Lambert staged Sarah's death as a car accident out of necessity, having learned that a mole within Third Echelon would use her as leverage against Sam. Lambert later concludes that he wasn't able to locate the mole, and that his efforts may have been in vain.
Grim later tells an enraged Sam to stop one of three EMP attacks at Michigan Avenue, stating that Sarah's designated apartment is within Michigan Avenue's blast radius; while Victor recovers Sarah and later helps Sam with halting the attack, Grim would accompany Reed to the White House in order to halt the assassination. Sam is extracted by Victor and has a brief reunion with Sarah before the two EMP attacks commence. Shortly after a crashlanding, Sam infiltrates the White House while confronting Black Arrow and Third Echelon operatives in the process. Sam regroups with Grim, who shoots Sam in the shoulder so that he can get close to Reed, appearing to be a hostage.
Upon entering the Oval Office, Reed prepares to execute Sam and the president. As Reed gets close to Sam, Sam disarms Reed and he and Grim kill the Third Echelon escorts. Sam interrogates Reed while the United States Army extracts Caldwell. It is revealed that Caldwell was going to shut down Third Echelon and leave "America vulnerable to future attacks", and to prevent this, Reed planned to frame Sam for assassinating the president, as supposed proof to the country that Third Echelon was necessary. Sam realises that Reed was the mole Lambert was looking for. Depending on the player's choice, Sam or Grim execute Reed. If Grim executes Reed, Grim confides in Sam that he is the only person that she can trust, but Sam says goodbye and leaves.
Black Arrow's interview with Victor has concluded, with Victor stating that Sam would be with Sarah and that Sam loved him like a brother. Shortly after Victor finishes his sentence, an explosion places the building on alert, implying that Sam is assaulting the base.
