A/N: A small snapshot of one of Donna and the Doctor's conversations, set sometime during early-mid series 4.
That Shoulder Which Props You Up
He sniffed, leaning back and casting his gaze upon the night's sky thoughtfully. "In the end I just got tired of it. Pretending. Resisting. She was..." he trailed off, his lips slowly curving into a smile. He let out a long breath and turned his head to look at his friend. "Oh, she was impossible not to love."
Donna smiled at him warmly. "I wish I could've met her," she said, taking him by surprise.
"Yeah?" he replied, his voice hitching. "Yeah. I'd've liked that. Mind you, the pair of you, together? The most stubborn women in the universe? My, that would be...that would be terrifying." He flashed her a grin, and she punched him lightly in the shoulder.
"But think how much happier you'd be, with her here," she murmured softly.
His brow furrowed, and he looked suddenly guilty. "I...I am happy, Donna," he tried to reassure her.
"Right," she answered disbelievingly, raising an eyebrow. "But you can't be as happy as you used to be."
The Doctor was silent, but his expression was anxious.
"It's alright, Doctor, don't look so worried!" she laughed. "I'm not resentful or anything. I know we have great times, the best of my life; but I also know how much she meant to you. How much you miss her."
He nodded, sighing heavily. "I'm sorry if I mope around too much," he mumbled.
Donna shook her head. "Don't be. It's completely understandable."
"I can't let go," he admitted abruptly, his voice going quiet. "I can't..."
Donna frowned, putting an arm around his shoulder and squeezing comfortingly. "Then don't."
"I won't," he whispered. "But I should. I usually...It's just. It's never...I've never...she's..." He hung his head, rubbing his eyes in frustration.
"You live your life in a way that's different to most, where you don't stop to see the fallout, the consequences," Donna filled in quietly. "Moving on, all the time, without looking back, 'cos if you look back, it's too hard. I reckon you've always lived like that. Am I right?"
He nodded slightly, and she continued, "But then Rose came along and changed everything, yeah? And you...you fell in love with her - " she paused briefly when the Doctor brought his head up sharply, unused to hearing those words uttered by anyone out loud.
" – and you can't turn that off, ever, so you're hurting," she continued. "You miss her, you love her, and you're hurting." She swallowed past the lump in her throat as she watched him blink, a solitary tear fluttering down his cheek and landing on the suit of his thigh.
"And I'm here, to be a friend," Donna told him decidedly. "To try and cheer you up and show you that life's still worth it. This life, travelling the stars, it's still worth doing, 'cos think about it, Doctor. All those planets out there, all those people; places you and her went and lives you both touched. Together. Memory after memory of different corners of time and space, and she was there, with you. Holding your hand." Her voice broke off with a hitch, and she held her breath.
Slowly, the Doctor turned his head to face her. "Donna - " he cut himself off, clearing his throat. "Thank you," he finished simply. "Thank you."
She smiled. "No problem, Spaceman." She paused thoughtfully, before saying, "And you know you said that she's really stubborn? And brave? And clever?"
"Yeah?" the Doctor replied, confused as to where she was going with that.
"Well," continued Donna. "Sounds like she's not going to take impossible at face value, eh?"
He swallowed thickly as he shook his head. "She can't come back, Donna. The walls have closed - "
" – Doctor," she interrupted him swiftly. "Don't just write it off. Don't write her off. You can still hope, you know. I've seen the most impossible things happen in the time I've been travelling with you. Maybe she'll surprise you. You've just got to believe in her."
"I do," the Doctor insisted. "But..."
"She loved you back, right?"
He smiled softly. "Yeah, she did."
"Well, then," Donna concluded, as if that was the end of the matter, "She'll be back."