The new Director of Homeland Security reunites the team when a nuclear powered Russian satellite is knocked out of orbit and must be diverted before it detonates over Southern California. The team races against time to stop an unstable ex-member of Scorpion, Mark Collins who kidnaps and threatens to kill Toby if his demands are not met.

Eccentric genius Walter O'Brien and his team of brilliant misfits continue to be the last line of defense against the complex, high-tech threats of the modern age as they solve extreme, life-threatening cases, including a global extinction event, a nuclear missile launch on U.S. soil, and even the perils of geniuses trying to start a family.