The meaty remains of a man who plays on the same bowling team as Brennan's dad (Ryan O'Neal) spew forth from the pinsetters, so Booth and Bones go undercover by joining the league as a couple.
Meanwhile, Hodgins is having panic attacks every ten seconds over Angela's imminent labor.
Booth and Bones find out that the victim was known to his teammates as the Closer or, "the gloater," rather – pretty much everyone in the league wanted to kill this guy. That's obvious from talking to the 12-year-old bowling ace and all the other teammates who seem overly invested in their hobby.
Looking over the evidence, Hodgins discovers some bone loose in the victim's skull and the team determines the bits come from a nose break. This could have been the mortal blow. So what are the red flakes they also found on the vicitim?
Before they can figure that out, Angela's water breaks.
Booth and Brennan look into the team members as suspects. One is an alleged car thief, and the victim is a known restorer of cars. The bowling league director known as The Raven busted the victim for putting superglue into his bowling ball. Another teammate named Hercules heard that the victim talked about him behind his back. Amber logs notes on her teammates in her computer.
While enduring heavy contractions, Angela tries to explain to Wendell how he can continue to analyze the evidence using her programs.
Booth and Bones play in a tournament with their team while Angela is in labor and Cam and Wendell try to figure out Angela's programs. In character, Bones keeps telling Booth that she'll never allow their future children to be like the competitive Amber. Booth isn't bowling so well and hopes new shoes will help his game. Bones figures out the lane had been recalibrated to make the pins closer together, and she speculates Amber could have done that.
Since bowling balls don't flake, Wendell has to figure out what the flakes on the victim's skull came from. He concludes they could have come from a motorcycle helmet. Bones asks her dad who on the team has a motorcycle. He says the shoe clerk rides one.
Booth investigates the shoe clerk's helmet, and sure enough, it's chipped. But the team implores the agent not to go too hard on the clerk because the victim was a horrible person who never washed his feet.
Back at the hospital, Angela has finally given birth – to a healthy, seeing baby boy.
As Bones and Booth walk away from the hospital, they discuss the meaning of parenthood. Bones smiles and tells Booth she's pregnant and that he's the father, thus ending season six.