Tony lets go of Bruce's wrist and slides his arm around Bruce's shoulders, holding him tight for a second and then loosening his grip, like a sideways one-armed hug. "Don't worry, we'll figure it out," Tony says. "It'll just lead us to a new understanding of matter and energy, that's all."

Perfect, perfect geeky reassurance. I would be comforted, too! (And yes, Bruce, that is exactly like a one-armed hug. Oh, honey.)