Barry, Caitlin, Cisco and Joe set a trap for Wells. Cisco uses himself as bait, which puts him in great danger. Meanwhile, Eddie makes a decision regarding Iris, which leaves Joe a bit unsettled.
Harrison, Cisco and Barry travel to Earth-2 to save Harrison's daughter. Barry assumes the role of his doppelganger, who's married to Iris. He then encounters alternate-Caitlin and alternate-Ronnie, who are Zoom's agents.
When Dr. Wells reactivates the Particle Accelerator, Barry must move the imprisoned meta-humans away. To do that, he needs help, and he chooses to ask Captain Cold for it.
James Jesse, a.k.a. The Trickster, once terrorized Central City twenty years ago. Now a copycat has arisen to carry on the name and resume his murderous misdeeds.