When you watch Scorpion Season 1 Episode 5 online, you see what happens when a malfunctioning nuclear reactor and a hated former Scorpion employee mix. It's not good. Mark Collins is a manipulative person, especially to Walter. The two of them go down the rabbit hole together and lose sight of everything but whatever they are working on. It's destructive behavior. Mark being back upsets everyone, especially Happy. Mark publicly humilates her, and then Walter takes Mark's side. When Happy runs a program behind Walter's back, the nuclear reactor starts its containment program. Not everyone makes it out. Agent Callo gets trapped, and there's also a pipe spewing radioactive steam. He has 10 mintues to get out of there. This means that Happy, Paige, and Mark have to go back to Mark's house in order to figure out a way for Gabe to escape. Thankfully, Gabe makes it out. Back at the house, Mark starts to get into Paige's head, making her fear that one day, Walter will discard her. As if that wasn't enough, Mark has been playing everyone. He manipulates the circumstances so that Walter will need him in order to save the day. Will Walter be able to get the code out of Mark before it is too late?