Cisco to the rescue, once again.

In tonight's premiere of The Flash, Barry (Grant Gustin) has been in the speed force for six months (in earth time, at least), and now there's an evil samurai intent on fighting him and only him, or he'll destroy all of Central City.

While the team knows and has generally accepted that Barry's in the speed force for a reason (because if he's not, the speed force will also destroy Central City), Cisco (Carlos Valdes) reveals in this exclusive clip that he's actually been working on a plan ever since the night Barry sacrificed himself.

Strangely, it's Iris (Candice Patton) who's most resistant to the plan, but she's got a point. How does Cisco know he can close the speed force? How does he know the speed force won't take Wally (Keiynan Lonsdale) instead? How does she know that Barry is even still alive?