A few hours. That confirmed Sam's suspicions, and also raised a number of questions. What was his universe like? Was he from a point in her past or future? Obviously, he knew a Sam, so that part was the same. So was the outfit, which she realized belatedly should have been a clue-- she still hadn't gotten used to the other Castiel's habit of wearing other things, so the return to the familiar had almost completely slipped by her. She had gotten used to overlooking some of the subtler differences between male-Cas and her own Cas, she supposed-- but obviously she needed to stop doing that, otherwise she might miss something incredibly obvious.
First things first, though. This Cas was dying, and whether it was her Cas or not, she wasn't just going to sit back and let that happen.
Except then his stomach growled loudly, and Sam's expression changed from one of determination to one of pure confusion. She tilted her head, looking at him in concern. "So when you said you're dying, you meant... dying of hunger?"
It would almost have been funny, except that it wasn't. Hunger was still an indication that something was seriously wrong. She remembered Cas, her Cas, experiencing hunger when Famine had been nearby, otherwise she couldn't remember seeing the angel demonstrate any interest in food. Liquor, occasionally, but not food.
There was an explanation to this that was coming to mind, but it was almost weirder than the idea of him being from yet another universe. Still, there were all sorts of possibilities that she was going to be forced to encounter here, that much was becoming obvious. "Cas-- are you human?"