"Sometimes you just have to run it out," says Barry, reaching down for Derek's wrist. It's so strange to see his own powers on someone else, and he stares at Derek's vibrating hand. "And don't put this through anyone on accident," he says, delicately placing Derek's hand back at his side.

"The good thing is, most Speedster powers can't really hurt you while you're getting the hang of them, and if they do, you'll heal. It's mostly property damage you'll need to worry about. Just stay full of calories and you'll be fine."