From the end of the whole ordeal until they got back to the TARDIS and set off into the vortex, Donna didn't take her eyes off the Doctor.
He was sort of… stumbling, she couldn't help but notice. Though initially sombre, he now seemed full to the brim with restless energy, and had hardly stopped talking in the last ten minutes. She didn't blame him; he did have quite a bit of conversation to catch up on. But his body didn't seem able to keep up with his mind, and as he dashed somewhat aimlessly around the console, rambling and flicking switches with shaking hands and leaning on the coral when he had to rest for a moment, she found herself growing a bit worried.
"Ice skating!"
Donna, lost in thought studying his rapidly tapping foot, looked up. "What?"
His face fell. "Were you listening at all?"
"Yes," she said indignantly, though in truth she'd lost him about eight minutes ago. "What about ice skating?"
"Well, we should go! Earth? Europa! Have I ever brought you to the, er…" He paused, and leaned heavily against the console, gesturing with his free hand as he tried to gather his thoughts.
"Doctor," she interrupted, before he could finish, "shouldn't you… I don't know, sleep? Or eat?"
"Why would I do that?" he asked, genuinely curious.
"Well, you-" She winced, knowing he wouldn't want to talk about it. "It's been a long day. Really, really long, apparently. And you're…" She nodded towards his arm, which was trembling visibly with the effort of holding him upright. "You're shaking sort of a lot."
He crossed his arms over his chest. "I don't need food or rest," he huffed. "Don't you think I've rested enough?"
"You shot yourself," she said, annoyance sparking in her tone. "You're clearly exhausted. Can you stop running around for once and just take care of yourself?"
"I went a little overboard, sure," he allowed, "but I'm still alive! So shh."
"Doctor," she warned.
Something in his expression flickered, then hardened. "I'm fine, Donna," he said firmly. "If you want to rest, feel free. I've got-"
Whatever he had, she never did find out, because his knees buckled abruptly and cut him off. She darted forwards to catch him, her heart lurching in alarm, but he was heavy and she didn't manage much in the way of slowing his fall. He winced as he hit the ground and she followed in his stead, the sharp grating digging into both their knees.
"Ow," he muttered. Seemingly giving up the charade, he let himself slump to the side with a great sigh, sitting half upright only with Donna's help.
"Are you okay?" she asked, looking him over with concern. "Are you hurt?"
"No," he said dejectedly. "Temporal-" he gave a vague wave- "weirdness, it takes a toll on you. I... suppose I might be, slightly, a tiny bit tired."
"Spaceman," she implored, "c'mon. Just rest, just for a bit. We can go wherever you like as soon as you're feeling better."
He pursed his lips, frustration and hurt mingled in his expression. "I don't want to rest," he said quietly. "Donna, I want- I want to do something, I want to move. It's been seven centuries, I-" He broke off, because his voice cracked and his lip trembled, and he had to sniff and glance away in an entirely useless attempt to stop her from noticing.
"Oh... oh, it's alright," she said, placing a comforting hand on his shoulder. "Hey, it'll be fine. It's not for long, you'll be all better in no time and then you don't have to stay still anymore."
He didn't seem to find this very comforting, but he set his jaw and stayed silent.
"You know you can't go running around in this state," she said gently. "Come on. Just for a bit."
Drawing a shaky breath, he rubbed a hand over his mouth. "I hate it," he mumbled. "Hate being bored. It... it hurts, I can't s- stand it."
"I know," she murmured. Even the thought of it made her heart ache for him; she couldn't imagine being cooped up in her own head for a day, let alone seven hundred years. "I'm sorry, Spaceman, I really am. But I promise, it won't last much longer. It'll go away, you'll be alright. We'll make sure of it, okay?"
He nodded, brows drawn together in disappointment, and she offered him a little sympathetic smile.
"We can put on the telly," she said. "You can tell me a story or two."
"Alright," he said quietly. He bit his lip, clearly trying to resign himself to his fate, and mumbled, "Thank you, Donna."
"Least I can do," she said. "I..." She swallowed around the lump in her throat. "I'm really glad you're okay. You scared me there, for a minute."
"Yeah," he sighed. "S'pose I did, yeah."
He wasn't arguing, but she knew he wasn't happy either. She could see something terribly akin to horror in his eyes, as he faced down another few hours of boredom, and she leaned forward to wrap him in a tight hug, which she really hoped conveyed just how sorry she was for him. It seemed so temporary to her, but he couldn't quite muster up a sense of perspective at the moment. To him, she knew, it was agonizing.
"From now on," she whispered, "you're not allowed around any more guns."
When she let him go, he shot her a weak, crooked smile. "Probably for the best," he admitted. "I don't think they agree with me."
Shaking her head, she helped him up off the floor. He swayed on his feet for a moment, shutting his eyes against a wave of dizziness, and after he steadied she refused to let go of his arm. The rapid tapping of his fingers on his thigh betrayed an energy that even he himself couldn't match.
"You're an idiot, you know," she said. She meant it as a quip, but a hint of concern sneaked into her voice against her will.
"Oh, I know," he said wearily. He nudged her with his shoulder. "That's what I've got you for, isn't it? Bedside entertainment?"
She scoffed, and dragged him (as gently as one can drag a person, and then some) out of the console room and off to bed.
