On Scorpion Season 4 Episode 12, Walter is upset when the rest of Team Scorpion doesn't want to take the job on Christmas Eve. He tells everyone that he doesn't need them; he can do everything himself.

What he can't do is walk down the stairs while carrying a box, apparently.

Walter falls down the stairs, hitting his head. He wakes up in an alternate reality where he's married to Florence, and he's a physics professor at USC. It's a crazy dream that only gets crazier.

Walter soon finds himself outside with Ray, who is his tour guide in this new world. They stumble upon a car accident where another Walter (Car!Walter) is trapped inside. He's dying. 

Car!Walter represents Walter in reality. He's bleeding out on the floor of the garage, but thankfully, Florence finds Walter and calls help. Quintis shows up next, followed by Sly who passes out at the sign of Happy drilling into Walter's skull, then it's Cabe, and lastly it's Paige and Ralph.

In Walter's hallucination, none of Team Scorpion know each other. He has to go recruit them all to save Car!Walter. Everyone in this new reality leads a slightly different life: Cabe is the LAPD Chief of Police, Happy hosts the Happy Mechanic Podcast, Sly is a video game mogul, Toby is a wold class motivational speaker, and Paige owns a restaurant empire.

What's clear is that everyone isn't as happy as they are in our reality because they don't know each other.

Thankfully, Team Scorpion saves Walter and Car!Walter. All is well.