Zoom realizes that Dr. Wells has returned to Earth-2 and issues a demand to the citizens of Central City to locate him. Zoom attacks S.T.A.R. Labs looking for Wells and Cisco, but they manage to escape with the Earth-2 Barry. Wells, Cisco, and Barry update Iris on what happened with the Earth-1 Barry, so they all set out to find Killer Frost in the hope that she will lead them to Zoom. After a fight, Killer Frost agrees to take the team to Zoom. The team arrives to rescue Barry and Jesse, but Zoom shows up too. The team is able to escape while Killer Frost keeps Zoom frozen and unable to move, but a third, unidentified prisoner is left behind. On Earth-1, Caitlin creates "Velocity 9", a compound to temporarily give Jay his speed so that he can stop a new metahuman named Geomancer. After, Caitlin discovers that when Jay uses Velocity 9 the serum starts to cure his illness. Jay, Caitlin, and Joe stabilize the breach and allow Barry, Cisco, Wells, and Jesse to return, but not before Zoom pulls Jay back through the breach to Earth-2.