In a hangar, an underground fight is held. The announcer Richtor Maddox lines up the fights while in a locker room, a man approaches a woman dressing for the match: Athena. They talk about the "big guy" until Athena tells him to leave. An alarm goes off and they grab guns and go out to see the "big guy," Titan, going berserk. They run away as Titan fights with… Clark Kent.
46 Hours Earlier
Clark is talking to Oliver on the phone when Martha comes in to mention that Clark has secretly been capturing criminal krypto-mutants. Clark is upset in the aftermath of Lex and Lana's wedding and releasing his frustrations on any krypto-mutants who get in his way, despite Martha's warnings. Through Oliver, Clark gets word of an underground fight circuit being broadcast over the Internet and involving krypto-mutants, and he and Chloe watch on the computer as the main fighter, Titan, kills a man with a spike that extends from his hand. Chloe can't track the signal or get past the security. They do freeze the frame on Titan and see he has a Kryptonian prison tattoo.
At the manor, Lana and Lex share a non-alcoholic drink and Lex comments on how Lana has been pulling away from him. Lex assures her he'll give her time and figures things will be different once the baby is born.
A short-tempered Clark arrives at Chloe's apartment and she's discovered the previous password has been changed. Chloe has identified one of the fighters, a krypto-mutant who was killed and returned to where he was kept at Belle Reve. Lois comes in and is desperate for a story for the Inquisitor, and Clark and Chloe quickly hush up their investigation. However, after they leave Lois spots the screen capture of the fight and recognizes the setting as an Air Force hangar.
Lois goes to the hangar and claims to be a dancer from a nearby strip club and needs some help. She gets by Athena and takes some photos for her story, but Athena comes back and tries to capture her. Lois attacks her and takes her down, but Maddox gets her at gunpoint.
Chloe has identified Maddox as the director of Belle Reve and Clark decides to talk his way into the ring to find Titan. Meanwhile, at the manor Lex discovers that his facility in Corto Maltese is compromised… by Green Arrow. He goes to talk to Lana, who is lying on the floor in pain. Lex has her taken to the medical center and Lex is forced to tell her that she's lost the baby due to complications.
Clark breaks into Belle Reve and confronts Richtor as he leaves for the night. Clark demands a fight and demonstrates his powers to Maddox to convince him. Maddox agrees to let him fight and takes him to the hangar, where Clark's first opponent is… Lois. They're forced to fake a fight and Clark uses his heat vision to destroy the equipment. Titan spots him and comes out to fight, killing Maddox when he gets in the way. Clark tells Lois to run right before Titan punches him with all his strength and Lois tries to run interference, without much luck.
Clark comes back for more and the hangar is torn apart in the ensuing battle. Titan knocks Clark down and prepares to stab him with his hand-spike, but Clark regroups and inadvertently knocks him back onto his own spike. Titan congratulates him on a good fight… and then dies. Clark gets Lois out.
Lex's man reports that they found the fight club but Titan was killed and they don't know who did it. Further, the autopsy reveals that Titan wasn't human.
At the Kent farm, Clark is going over photos of meteor craters and realizes there are probably more Phantom Zone prisoners. Since he doesn't know how to return them, the only way he can deal with them is to kill them. He confesses to Martha that he isn't sure if Titan's death was an accident and she tries to comfort him and reassure him his feelings mean he's human. Finally he admits his anger is over Lana and he thinks someone forced her to marry Lex, but Martha says at some point he has to let go.
Lana is in the nursery and tells Lex she's discovered that Dr. Langston was killed in a "car accident" the day of their wedding. Lex tries to reassure her without much luck and she wants to see Langston's files. Lex asks what he can do but Lana has nothing to say. Later Lex gets Lana's files from his family physician… and burns them.