"Yep, I know," Caitlin says, sunnily and undeterred. "This inoculation will keep you feeling fine. Given you've been exposed to all of us and you're going back to the place where this bug came from, you definitely want this."

Barry steps sideways and twists, trying not to let Yamato use him as a human shield.

"C'mon man, it's fine. Just a real quick thing," Barry tries to assure Yamato.

"Have a seat," Caitlin says, gesturing at a nearby chair. She's still cheerful about it, but it's obvious she expects him to comply.