In a new clip from "The Reverse-Flash Returns," the next episode of "The Flash," Barry encounters Reverse-Flash as he attempts to kidnap Christina McGee, the head of Mercury Labs. Unfortunately, in his astonishment, Barry blurts out some crucial information about himself as well as Eobard Thawne's future -- something Thawne may be able to use as he executes his nefarious plans.
According to the official episode description, "When Cisco (Carlos Valdes) gets a vibe of Eobard Thawne (guest star Matthew Letscher), Barry (Grant Gustin) and the team don’t believe it. But, after an attack at Mercury Labs, Christina McGee (guest star Amanda Pays) confirms that the Reverse Flash is back. Meanwhile, Iris (Candice Patton) and Francine (guest star Vanessa A. Williams) share a nice moment that brings Iris closer to her brother, Wally (Keiynan Lonsdale)."