Bruce has two kinds of sleep. When he's on edge, he can sleep lightly, ready to jump up at a moment's notice. When he's comfortable or not planning to have to run away in the middle of the night, he sleeps fine. More than fine, he sleeps hard. The rest is important because he needs to be as in control of himself as possible when he's awake, so he doesn't think that's a problem, unless of course he needs to get out of bed, and he's so deep into sleep that it takes him a while to come out of it.

When Tony calls his name, Bruce grunts and almost keeps sleeping, but the tug on the blankets pulls him to the surface enough for him to realize the urgency in Tony's voice. Is this real? Then the light comes on, and he's sure this is happening, not just some dream. He rolls onto his back and rubs at his eyes as he sits up, squinting in the light as he locates Tony.

"What's wrong? What happened?"