The team tackles their primary mission: stop a cataclysmic event that could change the course of human history.

The team’s first mission goes awry when a fatal mistake leaves them holding a ticking time bomb.

Clarke wants answers from the President. Abby performs emergency surgery. Octavia will do anything to find Lincoln.

Felicity’s past as a crusading hacker is revealed when someone uses a super virus that she designed to bring Starling City to a standstill. Meanwhile, Oliver and Thea work on…