A/N: Okay, this is the chapter I think all of you (or most of you) have been waiting for. Please review and let me know what you think!

xxxx

"I'm sorry, I don't know what happened," Rose said breathlessly as the Doctor carried her into the TARDIS. She'd just regained consciousness after a dizzy spell and an uncomfortable tightness in her chest had caused her to black out again. They'd only been on Foret for a few hours, and had been browsing market stalls when she had suddenly had difficulty breathing.

"Rose, don't worry. I'm going to find out what's wrong with you and get you better, I promise," the Doctor said, his voice full of concern and fear. He carried her through the ship, placing her gently on a bed when he reached the med bay.

"No," Rose weakly tried to protest. "I don't... I don't need tests."

The Doctor took her hand in his and brushed a piece of hair out of her eyes with his free one.

"Yes, you do. If it helps, I don't really like tests either, but they won't hurt, I promise."

Rose eyes pricked with tears, and she choked back a sob. "Please," she whispered, "please let me go to my room."

The Doctor shook his head and gave her a gentle smile. "I'm sorry Rose, I can't."

"Yes, you can. I just need to sleep, that's all. I had a bout of insomnia last night and it's exhausted me, that's all." She tried to get up, but the Doctor placed a hand on her shoulder and gently held her down.

"Rose, come on now. I'm just going to take some blood, check your blood pressure and link you up to a heart monitor for a bit."

Defeated, Rose stilled.

"Good girl." The Doctor got up and pulled a stethoscope out of a draw. "Lift your top for me, would you?"

"What?"

The Doctor smiled kindly at her. "I just want to listen to your chest."

Rose hesitated, then lifted her top. Despite everything that was happening, she was very aware of the fact that he was about to see her bra, and she blushed slightly, bringing some welcome colour to her pale cheeks. If the Doctor noticed this he didn't say anything, he simply placed the end of the stethoscope on her chest, completely professional. Rose gasped slightly as the coldness of the metal hit her skin.

"Sorry," the Doctor said, pulling the scope away and rubbing the end of it. He delicately placed it back down. "Better?"

Rose nodded, and started up at the ceiling.

"Okay, take a deep breath for me, then let it out slowly."

She did as she was told, but was too busy looking at the strange patterns above her to notice the look of worry on his face.

"And again," he said. She complied, and when he was satisfied he carefully sat her up. "Just need to do the back."

Ten minutes later, Rose was linked up to the heart monitor. Her blood pressure had been taken, which the Doctor had found to be worryingly low, and her blood was currently inside a little machine that was testing it for abnormalities. The heart monitor was currently beeping steadily, but much too slowly.

All of a sudden, the Doctor stood up from where he had been sat beside Rose's bed and briefly glanced upwards.

"What's wrong?" Rose asked, sounding slightly panicked.

He looked down at her, his eyes hiding something. "I think something's wrong with the TARDIS. I'll just go and check it out in case it's something that will affect the functioning of the monitor. Won't be long," he said, striding towards the door.

"You're leaving me alone?"

He turned in the doorway and smiled at her. "Don't worry, you'll be fine." He went back over to her and placed a small button in her hand. "Here, take this. If you need me just press it and I'll come running."

xxxx

"There had better be a good reason why you're making me go into Rose's room without her permission," the Doctor said to his ship and he walked the corridors, eventually arriving at his destination. He paused when his hand connected with the handle, hesitating only until the TARDIS gave him a gentle push. "All right," he grumbled, opening the door and stepping inside. He had noticed that Rose's room and been spritzed with a bit too much air-freshener recently, and today was no different. Gently closing the door behind him, he walked further in and just stood there, waiting for the TARDIS to give him some sort of instruction. She gave him a nudge towards the bathroom and he walked in, finding it a lot messier than normal. make-up was spread everywhere, compacts open and foundation sponges caked in the creamy coloured cover-up.

"Okay, so she's left it in a bit of a mess and looks like she's vigourously attacked her make-up. So what?"

The great ship sighed and brought him out into the bedroom again.

"What now?" he asked, getting slightly exasperated. "Oh, no," he said, moving towards the door. "I am not going through her diary."

But, as she had done with Rose, the TARDIS locked the door and wouldn't let him leave.

"You know I have my sonic screwdriver on me, don't you?" the Doctor said as she grumbled at him. "All right, all right." He hesitantly reached over to Rose's bedside table and picked up the colourful looking book, finding the last page that had been written on. "I shouldn't be doing this," he complained as he sat on the bed. He could hear the old girl shouting inside his head, and he looked back down and forced himself to read the last entry.

'I can't believe I just had to eat all those pancakes. It made me feel disgusting, and the TARDIS didn't help when she locked me out of my bathroom. I had to be sick in my bin in the end. How undignified. She doesn't understand. If I don't do this, then I'll never be loved. I've lost over a stone already, but it's still no where near enough. I stood in front of the mirror yesterday in my underwear and couldn't believe how hideous I still looked. The amount of fat I squeezed between my fingers was sickening.

The Doctor would go mad if he knew what I was doing. I don't think I'd be able to convince him that it was all for the greater good. He can be so stubborn sometimes. It will make him happy eventually though.

Must get ready now. We're going to the planet Foret, to visit a city called 'Um.' How funny is that?'

His hands shaking, the Doctor placed the book down beside him on the bed. "No," he said, getting up and walking towards the door. He pulled out the sonic screwdriver and aimed it at the lock on the door. Before he could press the button though, the device heated up in his hand and he yelped and dropped it.

"Stop it," he told his ship, cursing when he went to pick it up and it burned his skin again. "I said stop it!" he shouted, his voice trembling. "You're wrong. I don't care what her diary says... she wouldn't..." he trailed off upon being instructed to look under the bed. Kneeling on the ground, he peered into the dark space and caught sight of a large, metal box. He pulled it out and placed it on the bed. The box had a lock on it, and the TARDIS allowed him to pick up his screwdriver so that he could open it. Shaking even harder, he tried to keep his hand steady as he aimed the screwdriver at the lock. There was a buzz, and it clicked open. The Doctor stared at it for a moment, scared of what he'd find if he lifted the lid. He took a deep breath and opened it, instantly gagging as the smell of rotting food came wafting out. He slammed it shut and stepped away from it, his hands over his face. That was when he realised, when he shook away the cloud of denial that had been hanging over him. All those times Rose would take her her dinner to her room because she was tired, all those times he shrugged off the fact that he thought she looked thinner, drawn, exhausted. All those times he let her lie to him.

All those times he believed her.

Tears stung his eyes and he slumped down onto the floor, the shock hitting him like a lead weight. She was starving herself, and he hadn't even noticed. His shoulders shook, and he cried into his hands, wondering why she had done this to herself and inwardly yelling at himself for being such an idiot. She was slowly killing herself, her body slowly shutting down as it was starved of what it vitally needed. And she had been so clever, so devious that she had constantly thrown him off the scent.

But he was the Doctor, and he should have noticed.

It was Rose, and he should have noticed.

It was the woman he loved more than anything, and he should have noticed.

He sobbed despairingly. He knew all about the illness he now knew she had, and knew how utterly hard it was to come back from it. It frightened him to think that she wouldn't, frightened him to think that he could lose her all because he had been walking around blind.

He wiped his eyes and slowly got up. He had to confront her, even if it meant she would deny it and be angry at him for suggesting such a thing.

He had to save her.

If he didn't, Rose Tyler might die.

And then so would he.