Seriously, how did someone so bloody skinny weigh so much? It must be an alien thing, she decided, pointedly focusing on that (and half-counting down the steps until they reached the elevator) because having something that wasn’t please don’t die please don’t die don’t you dare die to think about was probably a good thing.
Soon enough they were at the elevator, and then he was saying something, almost too quiet to hear, and what she did hear didn’t really make much sense, because who was he even talking about? “What was that?” she asked, mostly just to keep him talking, because if he was talking he wasn’t dead, wasn’t slipping off and away and dying on her. She let go of him with one hand to reach up and repeatedly press the elevator call button a little bit frantically, hoping it would open soon and they could get down to where the doctors were and that he wouldn’t die in the meantime.
The doors opened, and she quickly readjusted her grip on him to drag him in through the doors, and she had a feeling if the situation were different they would look hilarious right now - her with her hair in all directions, half-frantically scooting a barely-conscious, ragdoll-limp Doctor around on the floor, into an elevator... it was like something that would be on a television show, a sitcom or something, only this wasn’t funny because he was actually bloody dying and she had to make sure he didn’t. Donna set him down and tugged his legs to the side slightly, so he wouldn’t lose a foot when the doors closed (that was about the last thing they needed, unexpected elevator amputations on top of some kind of freaky deadly alien poison) and then mashed the button for the lower floor.
“We’re almost there,” she said, as the elevator started to move, bending down so she wasn't absolutely towering over him, reaching out and putting her hand on his shoulder again, this time not shaking him, just resting it there, the action hopefully some kind of reassuring, “You’re gonna be all right.”