"Thank you," Caitlin says, then sets about swabbing Yamato's arm.

Barry grimaces a bit under that intense glaring, mouthing another 'I'm sorry' at Yamato. And Barry really is sorry! Even if he does believe it is a good and necessary precaution.

Ready now with the syringe, Caitlin gives Yamato a reassuring nod.

"Ready now? On three, one, two-- " She goes on two, delivering the shot with a practiced hand.