What Is That?
Disclaimer: Like everyone else, I don't own the Doctor or Donna or much else, for that matter. I just like to visit them for a little giggle now and again.
Donna Noble emerged from her bathroom in a cloud of steam, her hair freshly washed and wrapped up in a fluffy towel. She slipped on a comfortable pair of knit pants and hummed softly to herself as she sorted through the wardrobe, looking for a blouse to wear. Suddenly, the early morning tranquility of the TARDIS was shattered by a plaintive howl, "DOOOOOO-NNNNNA!" The Doctor's voice carried loudly through the ship.
Reacting to the horrible sound, Donna flung the towel from her head, grabbed a jumper and dragged it over her head. She ran, bare-footed and at full tilt, down the hall, oblivious to her wet hair soaking the shoulders of her jumper. She bolted into the Doctor's room but, looking around quickly, did not see him. She was beginning to get worried, and then heard a small moaning sound coming from the partially opened door at the far end of the room. She ran over quickly and pulled open the bathroom door.
There she saw a sight she would never forget as long as she lived: the Doctor sitting on the edge of the tub in his pyjamas, his head in his hands. He was repeating, over and over, "What?" and shaking his head. Donna, truly frightened by now, sank down on her knees beside him and said, "Doctor? What's wrong?" He just shook his head. "Doctor, please! Tell me what's the matter! Are you ill?"
The Doctor slowly raised his head and looked at her, his eyes wide with disbelief. He reached out and grabbed one of her hands. "Oh, Donna, " he said. "I don't know how this happened. It just came out of nowhere!" he said frantically. "I just looked up and there it was!"
"There what was?" she asked, quite concerned by now. Taking his hands in hers, she asked, "Is there an alien on board? Did it hurt you? Is it hiding somewhere? Shouldn't you be looking for it?" She knew she was rambling a bit, but she had never seen the Doctor so disturbed before.
Standing up quickly, he dragged Donna over to the mirror and said, "There! Don't you see it?"
"See what?" she said, a little confused. "Is there something in the mirror? Maybe it's just that little girl you told me about once."
"No, no, no, no, NO!" the Doctor said irritably. "Not in the mirror. There!" he said, his long finger pointing to a spot on the top of his head.
Donna leaned forward, peering closely in the mirror at the place he indicated, her brows knit together in concern. She stared, squinting, trying desperately to see what had caused the Doctor so much distress. Gradually her expression morphed from anxiety to disbelief to anger. She shot upright and, glaring at the Doctor, said, "Bloody hell! Is that what's got your knickers in a twist? A grey hair!
The Doctor grinned at her, relieved. "Yes! Exactly! So you see it?" he asked expectantly. Then he suddenly cried out, "Ow!" as Donna smacked him hard in the shoulder. "What did you do that for? That really hurt."
"I should hope it did hurt! That's for scaring me half to death. I thought there was something seriously wrong!" she shouted, grabbing one of the Doctor's towels and starting to blot her dripping hair.
"Something is seriously wrong, Donna," he said, a little bewildered at her response.
"Oh, you silly prawn!" she chuckled, started to see the humour in it all. "There's nothing to be so upset about. A little grey hair is perfectly natural."
"Maybe for humans, " he sneered, rubbing his still smarting shoulder. "But I'm not human. I'm a Time Lord. I'm only 903 years old. That's relatively young, for my people!"
"Listen to me, Time Boy," Donna said sweetly. "Grey hairs are a part of life. Everybody gets some at some point."
"You haven't," the Doctor countered.
"Well," she replied slowly, thinking about the box she picked up the last time they stopped to visit her mum and Gramps. "I'm a special case." Seeing that he still looked concerned, she continued, "You know, it could be something simple, like too many Jammie Dodgers and chips, and not enough vegetables in your diet. Or stress. Stress can cause temporary metabolic changes. Maybe you just need to take a few more holidays in between saving planets."
The Doctor mulled her words over for a while. Finally he said, "You're probably right. I'll just check myself out in the med-bay." Turning back to the mirror, he ran his fingers through his hair and said quietly to himself, "But what do I do about this?" fingering the grey hair.
Donna reached over, grabbed the offending follicle and yanked, hard. The Doctor yelped in pain and turned to look at his companion in disbelief. "Problem solved, " she said cheerfully, dropping it in the bin. "Now, Spaceman. Get yourself dressed and go make me breakfast!" And with that, she strolled back to her room, humming to herself.