Aaron was on the phone with Cassandra when she was kidnapped by Cole. Alarmed, he alerted the police.
When Cassandra decided to go to Haiti to fight a viral outbreak, Aaron argued with her, saying she didn't have to go, and suggesting she was obsessed with Cole's story of an apocalyptic pandemic.
Aaron ran into Cassandra and Cole at a fundraiser and helped get them in the door. He and Cassandra had a brief and tense discussion about the end of their relationship, in which he said her story about Cole being a time traveler was crazy and suggested she needed psychological help. After Cole and Cassandra were arrested for trying to kill Leland Goines, he angrily accused her of using him to get to Goines.
He showed intelligence photographs of Cole's accidental trip to North Korea to Cassandra, claiming Cole was dangerous and saying he wanted to protect her.
After Cassandra was abducted by the Pallid Man, Aaron was kidnapped by Cole, who forced him to help him find Cassandra. They had a short conversation where Aaron explained what Cassandra meant to him. Using the Pallid Man's penchant for flowers, they managed to track down Cassandra and free her from the Army of the 12 Monkeys. Cole splintered in front of Aaron, causing him to realize that Cassandra's story was true. Aaron apologized for doubting her and resolved to help her fight the plague.
Aaron stole classified files on Operation Troy from Senator Royce and discovered that the CIA plans to use M5-10 to assassinate Adam Wexler. He made copies of the files and shared the info with Cassandra. They informed the CIA that Operation Troy had gone wrong, and the CIA agreed to work with them and Cole to stop the virus. Afterwards, the CIA threatened them with prison, but Aaron told them he had given the files on Operation Troy to a friend who would leak the story to the press if anything happened to them. The CIA relented and let them go.
Later, Aaron urged Cassandra to go to Chechnya and make sure Cole had really been erased from the timeline so that she could have closure.
Cassandra and Aaron had renewed their romantic relationship and were enjoying an intimate moment when Cole appeared, surprising both of them. Aaron reacted angrily, saying Cole had no idea how to stop the plague and that he would get Cassandra killed. Later, he reluctantly agreed to continue helping Cassandra try to prevent the plague. While on the trail of the M5-10 virus, he encountered Olivia, who asked him what he would do to save Cassandra. Afterwards, he and Cassandra talked about Oliver Peters' decision to risk the lives of billions by recreating the M5-10 virus in order to save his husband. Aaron sympathized with Peters and suggested the most important thing was to protect those closest to one, while Cassandra disagreed.
After Royce announced he would run for president, Aaron showed up at Cassandra's bookstore drunk. He told her he had been fired because his involvement in Operation Troy meant he brought too much baggage to Royce's campaign. Despairing, he suggested that he and Cassandra give up trying to stop the plague and use their foreknowledge to find a refuge and ride it out. Later, he met with Royce and expressed his interest in a private sector project to provide shelter for selected individuals in case of a disaster. Royce agreed, saying he needed someone to "spearhead" the project.
Aaron revived Cole when the latter went into cardiac arrest. Later, he left Cole and Cassandra, saying that stopping the plague was not his fight and that ensuring Cassandra's safety was his greatest concern. He met with Olivia to make a deal, demanding that the Army ensure Cassandra was protected from the plague. He gave up Cole's location to the Army, and tried to take Cassandra to safety before the Army attacked. She refused, struck him, and ran, and he called out after her that the plague was inevitable and that he was only trying to protect her.
Cole captured and interrogated Aaron about the Army. Aaron refused to talk until Railly appeared, which broke his resistance, and he told them that Olivia was an investor in Markridge. Aaron broke free and tried to run. Cole pursued and the two men fought, accidentally setting the room on fire. Aaron was trapped under a fallen shelf in the middle of the flames, and Cole persuaded Railly to leave him.
|"Splinter"||"Mentally Divergent"||"Cassandra Complex"||"Atari"||"The Night Room"|
|"The Red Forest"||"The Keys"||"Yesterday"||"Tomorrow"||"Divine Move"|
|"Shonin"||"Paradox"||"Arms of Mine"|