Booth plays hockey while the team cheers him on. Bones asks why Booth is knocking players over. Booth then is sent to the penalty box for charging an opponent. The team educates Bones on the rules of the game as Booth shouts to be let out of the box. After an opponent knocks down Booth's teammate, who happens to be the intern Wendell, Booth and the opponent begin to fight. The team watches as Booth beats the man repeatedly in the head. Booth helps his teammate up and the two exit the ice. Bones says she's not sure how she feels about the game.
Booth goes back to the locker room. Bones walks in and asks if they're alright. She asks Booth if he broke his hand. The guys tell Bones to wait outside.
A dad and his son Leo go ice fishing. They drink beers and the dad uses ice fishing metaphors to tell his son to have safe sex. Leo drills through the ice and blood comes up through the ice. They brush the snow away and see a man frozen under the ice.
The team investigates the body in the ice. Bones says she's not sure if it was murder. Bones tells Booth to stop scratching under the cast on his wrist. Booth then sees something on the body. He pulls up a necklace and says the body belongs to the guy he knocked out at the hockey game. Booth says he's a suspect.
Caroline says Booth is a suspect, so Bones will have to work the case with Agent Payton. Bones says she won't work with anyone other than Booth. Booth smirks and asks who wants to interrogate him.
Camille says the time of death was five days ago. Wendell says that if Booth is a suspect, he should be too. Camille reminds him he was being taken care of by his mother for his hockey injuries.
Payton talks to Booth about the hockey game. Booth says he was mad that the guy hit two of his players, but not mad enough to chase him down after the game. Payton says she has a witness who says he said he threatened to fight the victim off the ice. She then asks if he thinks his family's history of alcohol abuse has made him more prone to violence. Booth gets up and leaves. He confronts Sweets and asks why he's there. Sweets says he has to observe the interview. He then asks if there is sexual tension between him and Payton. Sweets then asks if Booth has his rage under control. Booth tells Sweets to never bring up his old man again, then leaves. Booth returns to Payton and she asks if he works out much.
Wendell says he found the cause of death was a projectile through the left eye. He says there was no bullet wound, so he doesn't know what kind of projectile it was.
Booth, Payton, and Bones go to Pete's apartment. His girlfriend says Pete was a volunteer fireman. She says someone slashed Pete's tires before he disappeared. Booth asks why she didn't report him missing and she says she thought he was seeing someone else. They see a note with the name Albie on it and ask Pete's girlfriend if she knows who it is. She says no. Bones sees Pete's fish are all dead and floating in the tank. Payton sees past due bills and says Pete looks like he couldn't afford to pay the bills. Bones sees blood on Pete's hockey uniform. Booth says it's not surprising. Pete's girlfriend says Pete asked her to borrow $2000. She says she thought that meant he liked her. Bones is confused, but Booth tells Pete's girlfriend she's absolutely right.
Bones goes back to the lab and Camille tells her about the cause of death. Booth sees Pete's tooth is cracked. Camille says he was a hockey player, so that's pretty normal. Hodgins walks in and says the water in Pete's throat was not from the lake. He says it was deionized brine water. Bones suggests that it was from the ice rink. Hodgins says yes and says Pete was killed in the rink, then dumped in the lake. Bones says it's interesting that all the evidence points back to Booth.
Booth and Payton interview hockey players. They say Pete was a fighter and wouldn't go down easily. Two players tell the detectives that Pete got into a fight with a guy named Lou at the last game. They tell the detectives to talk to Chloe, an ice skater who sleeps with all the players.
The detectives talk to Chloe and she says she and Pete had a casual relationship. Chloe says they had an open relationship, but she knows he wasn't sleeping with anyone else. Booth says he was, then Chloe asks who. Payton then tells Chloe they think she killed Pete. Chloe then admits she knew he was sleeping with someone else. Payton asks who Albie is and Chloe says it is a guy who runs a poker table. Chloe then asks who Pete was sleeping with and the detectives leave.
Bones looks at the skeleton and sees a pattern that looks like he was struck repeatedly. Wendell says the padding would have protected him, so it wasn't during a game. Wendell tells the doctors he missed something. Bones scolds him and he runs off. Camille tells Bones she was supposed to tell him anyone would have missed that. Bones says Booth says she sucks at non verbal communication. Booth and Payton go to the poker room. The men all draw their guns as the detectives walk in. Booth tries to explain that they don't care about the illegal gambling, they just want to talk to Albie about Pete. Albie steps forward and says she wouldn't kill someone who owed her money. Albie says Pete had paid up in full using a bracelet. She hands it over and tells the cops to leave.
Booth, Bones, and Payton go to the ice rink. Bones explains that rink ice was found in Pete's throat. Bones says there should be blood somewhere on the ice. Booth turns on the blacklight disco light and the detectives look for a big puddle. They find a large bloodstain and figure it is where Pete was murdered.
Hodgin's examines the melted ice from the rink for DNA that matches Pete. Wendell says he can't figure out what the murder weapon was. Angela pulls up an image of the blood smear to try to figure out where the body was dragged. Wendell notices drops of blood that parallel the smear. Angela says the parallel drops don't belong to Pete, but more likely belonged to his killer. Hodgins realizes he needs to check the ice for DNA that isn't Pete's. They then wonder what killed Pete's fish. Wendell says that they didn't starve to death because they would have eaten each other first.
Sweets tells Booth that he is a viable suspect in a murder case. Booth teases Sweets for being the one to determine whether or not he could be a murderer. Sweets tells Booth he saw him beat a man on the ice. Booth says it was hockey. Sweets points out that Booth joined the army, became a sniper, then joined the FBI. Sweets says Booth has a pattern of violence and he should face the fact that the violence from his childhood is affecting his life. Caroline then walks in and tells Booth Pete's phone records are in. Booth walks out and tells Sweets he's killed, but never murdered.
Wendell and Hodgins examine the fish. They figure they all died at the same time. Wendell says he doesn't understand how the fish fit into the murder. Hodgins laughs and says Bones says you figure out the facts about everything, then see how they fit together.
Payton sees that Pete called the same number 8 times before he was murdered. They see the number belongs to Lou. Caroline tells the officers to call Lou in for questioning. Booth tells Payton he knows how to get blood samples. He says there is a game tonight and sometimes during games, people bleed.
Booth cuts off his cast. Wendell tells him he shouldn't play yet, but Booth insists. They then make a plan to get a sample of Lou's blood since he is the prime suspect in Pete's murder. In the stands, Payton asks Bones if Booth is always flirty. Payton asks if Booth twinkles at everyone and Bones says no. The game then begins and Bones takes notes. Wendell gets the sample they need and Bones collects it. Payton takes pictures while Booth messes with Lou on the ice. Booth then knocks out one of Lou's teeth. Lou spits out blood then knocks Booth out cold.
Booth imagines that he is playing hockey with Luc Robitaille. Booth tells Luc he can't play hockey, he has to solve a murder. Luc tells Booth to forget the blood. Luc says to look at the team and see what brings the team together. Luc then tells Booth he's not his father. Booth snaps out of it as Bones calls out to him. She helps him up and escorts him off the ice.
Hodgins tells Angela the fish died of ammonia poisoning. He says someone must have cleaned the tank with window cleaner. Hodgins asks how things are between Angela and Roxie. She says fine, then asks if he is seeing anyone. Hodgins says he had a first date and asks if Angela is jealous. Angela then says Pete's apartment was a mess and it looked like he never cleaned anything.
Sweets goes to Booth and asks about his head injury. Bones says Booth has a concussion and shouldn't fall asleep. Booth tells Sweets about his hallucination. Camille walks in and says the blood doesn't belong to Lou. Sweets tells Booth his vision may have been telling him something. Booth then asks Bones to take him home.
Wendell and Hodgins go back to Pete's apartment and look for the real source of the ammonia poisoning. Hodgins digs in the tank and retrieves large amount of jewelery. They tell Camille about what they found. Caroline is annoyed that they tampered with a crime scene. Camille says no chain of evidence had been breached. Payton speaks up and agrees with Camille. Caroline then says the items were reported destroyed in a fire. They remember that Pete was a fireman and suggest that Pete was stealing from fires to pay his debts.
Booth looks over Pete's team roster. He notices that they all played on the same high school team. Booth wonders what brought the team back together. He tells Bones that Pete's team are all fireman and play on the same team. Booth finds an instrument on Booth's uniform. She asks what it is and he says it's a lace puller. She says it could be the murder weapon.
Pete's teammates are called in for questioning. The detectives ask if Pete broke some kind of fireman's code and Ed says something like that. The others refuse to say anything else without a lawyer. Bones says they know a lace puller was the murder weapon. Booth then asks Ed if his professional hockey career was ruined by a fight with Pete. Booth then asks about the stolen jewelery. Bones says it's only a matter of time before they find out who killed Pete. Ed admits he killed Pete. He says he confronted Pete about the stolen jewelery and Pete said he wouldn't do anything about it because he was a coward. Ed says Pete was wrong.
Booth takes Bones ice skating and she falls. She says she has natural athletic ability and Booth teases her. Bones asks Booth about Payton. She tells Booth that he is the only FBI agent she wants to work with. Booth confides in Bones that Luc told him he was not his father. The two then skate around the rink and laugh.