Toby has his first boxing match. He's got the music, the nifty name (the Raging Id), but what he doesn't have his Happy. Oh, and he doesn't have a victory either. He gets knocked out.
Ralph and Paige are trapped on a subway train that's on a rampage. It's going 80 miles and hour and getting faster. Ralph and Paige try to help as much as they can on the train while Team Scorpion tries to solve it from the outside. When that doesn't work, Walter jumps onto the train.
Team Scorpion figures out that the runaway train was a distraction. It was done so someone could break into LAX to steal a bunch of British gold coins. It is a two man op: one guy is the thief while the other controls the runaway train from a remote location.
Walter sacrifices himself in order to save Paige and Ralph. Oh, and everyone else, but that's not who Walter was concerned about. Walter manages to save the day, but he gets rewarded with a slap from Paige.
Ray helps Walter to see that putting distance between yourself and the people you love isn't the best course of action.
It turns out that Happy and Chet aren't dating. Chet is Happy's comedy coach.