Six Flags Great Adventure is days away from opening, and many thrill seekers will be headed for The Flash: Vertical Velocity coaster, the first "super boomerang" roller coaster in North America.

the team races to find Zoom's lair by asking for help from the most unexpected source on Earth-2. Meanwhile, back on Earth-1, Caitlin rushes to perfect Velocity-9 so that Jay can stop Geomancer.