Lexon is a monotheist and a Soldiers of the One cadet whom Lacy Rand meets on the jump ship bound for the STO training camp on Gemenon. He befriends her, Devanna and Odin Sinclair. Diego is their STO teacher. He tells them a little bit about the Church and what to expect at the camp.
The Apolli, a Gemenese polytheist terrorist group, captures and boards the jump ship. They take the passengers hostage. They begin executing them in the names of their gods unless the cadets repent of their monotheist beliefs and turn back to the Lords of Kobol.
Lexon, Lacy and Odin Sinclair stop the Apolli from executing more passengers. It is later revealed that this was an STO initial placement exercise. Diego says they needed to find out how the cadets would function under stress - who would crumble and who would step up. No one was actually killed. The deaths were faked and dummies were jettisoned into space. ("Blowback")
At the camp, Lexon is late for Kevin Reikle's weapons class. He runs past a guard without saluting. The guard yells at Lexon to salute and the two get into an altercation. The guard tells a U-87 robot to execute Lexon. Lacy witnesses this and tells the robot to stop, which it does. The guard and Lacy go back and forth ordering the robot. The cylon ultimately follows Lacy's orders and Lexon's life is spared. ("The Heavens Will Rise")
Because of this, Reikle and Diego order Odin to kill Lacy. It seems as though Odin is going to follow through with the plan. Lacy is taken aback. Reikle and Diego tell Odin to do it, but Odin suddenly shoots at Diego and Reikle. The gun only clicks. It is empty. Diego and Reikle were testing Odin and he failed.
Diego grabs Lacy. Lexon suddenly appears and shoots Reikle dead. Then Devanna emerges from her hiding place and shoots Diego dead, freeing Lacy.
Instead of leaving Gemenon as they wanted to do, Lacy brings him, Odin and Devanna to where the U-87 robots are kept. Lacy orders them to power up and follow them. They have work to do. ("Here Be Dragons")