|“||It's not over. No victory...without sacrifice.||„|
|~ Nestor's last words on Brace for Impact|
Nestor Lozano, also known as “Catalan”, was a former soldier, CIA operative and wanted mercenary who was a member of the "True Believers", the conspirators responsible for the explosion that decimated the Capitol Building during the State of the Union address. He was an army major who was in Peter MacLeish's unit during his time in war and after the latter spared his life, Nestor felt indebted to MacLeish.
Nestor has carried out assassination missions for the cause of the conspiracy. He was assigned to kill Majid Nassar to prevent the latter from giving out too much information on the conspirator's activities and later on to kill Tom Kirkman to allow Peter MacLeish to obtain the presidency. The latter task failed and Tom Kirkman survived and was promptly targeted by special armed forces. Once a decoy impersonating Lozano was killed, Nestor was able to resume his activities. During a final confrontation with Hannah Wells, he was fatally impaled by reinforcing bars, however not before he gave Patrick Lloyd access to the Defense Department's most highly classified server.
Nestor was with Peter MacLeish during the latter's service in the military. According to Alvin Joyner, he was escorted on a covert meet with an Afghan warlord to deliver five million dollars in cash. However, the meeting went south, the warlord took the money and turned on them. He, along with MacLeish's unit, fought his way out of the compound, but the warlord continued to pursue. It was at that moment the unit disregarded the rules of engagement and decided it was either kill or be killed and went as far as to kill innocent civilians. Not long after, Nestor confessed that he was CIA officer with five million dollars to help with the war efforts against the Taliban. MacLeish's unit then wanted to kill him out of retribution for their lost comrades, but MacLeish stopped them, stating that Nestor was only following orders. This would be how Nestor felt indebted to Peter. At some point, he and Peter would join in the conspiracy against the U.S government.
Nestor paid Al-Sakar to claim responsibility for the Capitol bombing, adding that he also wanted "death to America".
Catalan and a group of men were chasing Sammy Serafian who confirmed a direct link between Al-Sakar and the dysfunctional explosive found at the Capitol wreckage. They were able to capture the man, but not before he sent the information to the U.S government. Catalan took the laptop he used and left.
During Peter MacLeish's swearing in as Vice-President, Catalan entered a building facing east toward the Capitol, eluding the guards within it. Inside, he assembled a silenced sniper rifle and prepared to assassinate President Kirkman. Unfortunately for him, Hannah discovered his location and shot one round at Catalan, which ricocheted off the building and caused Catalan to flinch. He managed to land a bullet in President Kirkman, who sustained life-threatening but non-permanent injuries. A decoy who was supposed to be Lozano left the building.
After President Kirkman entered surgery from wounds sustained from the attempted assassination, Peter MacLeish was sworn in as acting President and quickly ordered a raid on the building "Catalan" was hiding out in. Going against the advice of military advisers and Chief of Staff Aaron Shore, MacLeish chose to kill rather than capture "Catalan". After the decoy was killed, the real Lozano left the building.
Some evening later, he departed a helicopter with dozens of members of the conspiracy awaited. After the conspirators ran Jason and Hannah out of the landing site, they left the area two hours before the FBI arrived.
Nestor and some other conspirators kidnapped Hannah while she attempted to exit a motel. He was called by Jay Whitaker to inform him of his progress.
The next morning, Nestor and his colleagues locked Hannah inside a storage container and texted to Whitaker and Patrick Lloyd that Hannah Wells had been taken care of. Later that day, he spotted Jason Atwood spying on Jay and Patrick and promptly shot him with a silenced pistol.
Nestor gave Hannah Wells Jason's ring as an indicator that he was killed. He explained that she killed Peter MacLeish, whom he treated as a brother and he killed Jason in retribution. Nestor then knocked out Hannah with a syringe and put her in the back of a van loaded with explosives.
Using a fake I.D made by Jay Whitaker, he took on the alias of David Farell and went inside the Pentagon to hack into the Defense Department. Once this was done, he left but not before Hannah Wells caught up to him. The two engaged in a violent chase while ramming each other's vehicles. Nestor was t-boned and was forced to flee by foot. Once Hannah caught up to him in an apartment building under construction, Nestor and Hannah engaged in a final confrontation, only for him to be impaled by reinforcing bars in the ground. Nestor gloated that it was not over yet and recited the True Believers' slogan, "no victory without sacrifice" and succumbed to his injuries.
Nestor was cold, callous and ruthless whenever he was assigned a task. When preparing to kill Tom Kirkman, he did so as if in a casual manner and showed no signs of remorse. He was a devoted member to the conspiracy, as he killed Majid Nassar in order to stall the investigation into it. As such, he, along with other members of the conspiracy have a detestation against the United States.
However, as a former soldier, Nestor also appears to have some sense of honor. When Peter MacLeish stopped his unit from attempting to kill him, Nestor felt indebted to MacLeish and felt as if they were brothers. Although Peter was killed by his wife, Nestor assumed Hannah was the one who killed him and so he killed her partner, Jason, in retribution.
- Until Lazarus, Nestor had no on-screen dialogue.