James L. Lennox was an undercover CIA agent who tried to infiltrate Enzo Markovic's lab. He was captured by him and Markovic became a doppelganger of Lennox himself. Lennox was also engaged with Emma Wallace, who was killed by Markovic.
Season 2[]
Lennox was captured off-screen and tortured for four weeks by several of Markovic's doctors. Unbeknown to Lennox, his fiancee was sleeping with a faux Lennox and wound up getting captured by him as well, only to be killed after she was strapped with several blocks of C-4.
After interrogating Arden Jezek, Sydney and Vaughn located Lennox at the bottom of Markovic's office, where he was being tortured by the doctors. While leaving, Sydney and Lennox were ambushed by some of the guards, but Lennox risked his eyesight to save Sydney and shot the assailant in the back. While heading back to the CIA Headquarters, Sydney told Lennox that his fiancee was dead.
Lennox arrived to the CIA HQ and explained that himself and agent Wallace had infiltrated Markovic's entourage as part of their deep cover mission. Lennox asked about Emma once again, only to learn that agent Emma Wallace was killed, Lennox informed the team that him and agent Wallace were engaged, Lennox was then taken to a safe house. Sydney later went over to the safe house to bring agent Lennox some groceries, but found him drunk at the kitchen table, upset about his fiancee's death. Sydney told Lennox about Danny and told him that she preferred feeling all of it instead of nothing, then took the bottle from Lennox. In a moment of weakness, Lennox kissed Sydney but she didn't kiss him back, making him realize his mistake. Moments later, CIA agents arrive to arrest agent Lennox again, having learned that Dr Markovich had genetically altered himself to look like agent Lennox. To verify if he was the real agent, tests were run to look for a flaw in his eyes, the only indicator to tell the clones apart from the real person.
Once it was confirmed that he was the real agent, he informed the team that he was meant to be with Emma in Berlin the day she was killed, but Dr Markovich had already captured agent Lennox and taken his place which is the reason why Emma hadn't been able to report in that day. The team found the prototype lab in Polan at train yard, Sydney and Lennox were tasked with the mission of obtaining data from Project Helix as well as destroying the lab to prevent the production of any more clones. Once there, both agents took down the guards around the train cars and entered the lab. While Lennox was copying the data to a disc, they found out that another clone had been made, but not other information was available. At CIA HQ a frantic call comes in from a person claiming to be the real agent Lennox also in Poland heading towards the lab in the train yard, according to this "Lennox", the eye test was a complete joke and there is no way to tell the clones apart. Agent Vaughn orders the man on the phone to stand down and stay away from the train yard but the connection is poor and the call is dropped. Agent Vaughn contacts Sydney only through coms and informs her that there is someone heading her way claiming to be the real agent Lennox while the other is Dr Markovich, Jack Bristow informs Sydney that she must dismarm and contain both men until the CIA can sort everything out. Sydney takes agent Lennox's gun and has his handcuff himself to a pipe while she heads out to the other agent Lennox.
Agent Lennox eventually frees himself and goes out to find Sydney and the other agent Lennox. Sydney finds them poiting their guns at each other while they try to convince her who the real agent Lennox is. Unable to identify the real one, Sydney pulls out the detonator for the C-4 in the lab, knowing that Dr Markovich would try to stop her from detonating the charges, as she presses the button, Dr Markovich aims his gun at her only for agent Lennox to shoot him three times in the chest as the lab blows up.
Agent Lennox and Sydney see each other again in LA where he tells her that he's going on a four week vacation to Fiji where he and Emma were planning to have their honeymoon, telling her also that this is where Emma Wallace was from. The two share a bittersweet moment as they think of the people they loved and lost.