It's time to reunite Team Scorpion! Cabe had been working as a tech advisor on a movie. Walter's been doing therapy, and he is suffering from dizzy spells. His hand isn't back to full capacity yet.
Another big change is Paige has been put in charge of the business aspects of Scorpion. She's decided that the office needs an open communication policy, so she tells Walter that she kissed him in the hospital.
Adriana Molina, the new head of Homeland Security, reassembles Team Scorpion to stop a nuclear Russian satellite from hitting California. After numerous missteps, the team figures out the best way to stop the satellite is to hit it with an EMP.
Meanwhile, Walter struggles being back in the field. The dizzy spells have rocked his confidence. They tend to come at the worst time, like when he is on the side of a hot air balloon up near the satellites' orbit. To make matters worse, he lost his parachute, and now him and Paige are up in the air with only one parachute.
Oh, and their plan to redirect the satellite's path worked! It's heading towards the ocean, but in order to get there, it is going right through Walter and Paige. Thanks to some creative parachute maneuvering, they manage to land safely.