Richard Elia's hired Team Scorpion to help with his Smart House. The night before the big launch, Walter followed Ray's advice and mingled at a tech expo. There, he met a woman named Stella who drugged him and planted a virus on Walter's computer that was put into the Smart house code. This is what you get for trying to be normal, Walter.
The house is locking people in and it is quickly filling with smoke. While Cabe and Paige go off to find Stella, the team is trapped in the Smart house trying to solve the problem without dying from smoke inhalation. The house seems to know every move the team makes, which makes things difficult.
Sylvester is trapped with three kids. Happy and Sylvester battle the house together, and eventually catch up with Toby. Walter comes up with a way to stop the fire in the server room - deprive it of oxygen. The only catch is Toby is in there too. Walter decides it is worth the risk.
Toby survives, but it's a close call. There are actually a lot of those going around. Sylvester almost falls off a building. In the end, Team Scorpion figures out it was an inside job, and saves the day like they always do.