Rose sat beside Jack, stroking his head whilst the Doctor tapped at the keys of a computer. He had come to the conclusion that Jack must have been infected by something at Torchwood; there was no other explanation. This of course meant that the Doctor now had no reason to let them continue with their experiments and would shut them down as soon as he knew his son was all right.
"Come on baby," Rose murmured to her child as the Doctor tapped at the computer.
The Doctor paused after a minute, sitting the opposite side of the bed to Rose, his hands clasped tightly as he pondered what to do.
"What's wrong with him?" Rose asked in a whisper hardly daring to breathe.
"I don't know," the Doctor admitted. "They've obviously invented a disease that affects Time Lords but I've never seen anything like this before."
"So you can't cure it?" Rose said biting her lip as tears threatened to fall.
"I don't know," the Doctor replied. "But I'm guessing Torchwood is responsible for this illness, so they probably have the cure."
Rose swallowed hard and tried to blink away the tears.
"So you're going to have to go back out there to get it?" She said quietly, watching Jack's chest rise and fall with each breath.
"Yes," the Doctor nodded. "You'll have to stay here with Jack."
"Oh no, you're not making me stay here," Rose said firmly. "Jack can look after Jack and I'm coming with you. Torchwood want you as their captive and the last time you wandered willingly into their midst you regenerated."
The Doctor couldn't help feeling a little pride at the stubborn loyalty of his partner. He knew he wouldn't be able to talk Rose out of coming with him.
"Alright," he agreed. "But don't start a fight."
"And I want you home by midnight," Rose said repeating the words she'd said all those years ago on platform one, their first adventure together.
"You get Jack, I'll just make sure this one isn't going to break into a fit or anything any time soon," the Doctor stood up and then paused halfway between the bed and the medicine cupboard. "By the way, who's Charlie?"
"I think, from what I've seen, he's Jack's boyfriend," Rose said grinning weakly at the Doctor as she went off to find her friend.
It didn't take her long to reach Jack's room and explain what was happening. Jack immediately agreed to look after baby Jack and Charlie said he'd stay with them.
Rose then met up with the Doctor again in the console room. His face was etched with worry and Rose found her stomach sinking.
"Ready?" He asked, holding out a hand to her. She took it, squeezing it gently.
"Yeah," she replied. "Got a plan?"
"Nope," the Doctor said, opening the TARDIS doors and glancing around before stepping out.
The TARDIS was surrounded by Torchwood personnel. Yvonne was in the thick of them, glaring at the Doctor and Rose.
"Think you can just stroll about like you own the place do you Doctor?" Yvonne was practically growling at them and even Rose, who blamed this woman for her sick child, felt a little intimidated.
"Yup," the Doctor replied in a cheerful voice though his face displayed no hint of a smile.
"I hope you know that when we catch them your friends Jack Harkness and Charlie McKay will be executed," Yvonne said, her hands on her hips.
"Good job you'll never catch them then, isn't it?" The Doctor said just as fiercely.
"That's what you think-"
"That's what I know," the Doctor cut across her, leaving Yvonne looking more livid than ever. "Now, I'm going to be very patient and ask you a few questions. I want you to answer them."
"And why exactly should I do that?" Yvonne scoffed, looking the Doctor up and down with disgust.
"Think about it! You're human, use your brain!" The Doctor said heatedly. "If you don't answer them then I will have to find the answers myself. It would be so much easier just to give them to me. So, what have you infected Jack with?"
Yvonne stood looking at him for a minute as though trying to decide her best plan of action. She took a step away from the surrounding guards and stood right in front of the Doctor.
"It's a new serum that we've been working on for some time," she said quietly. "You, quite by chance, stumbled in just as we had perfected it and required a test. If the serum works properly your son will be dead within the next four hours."
Rose felt her breath catch in her throat. Yvonne was looking at her with a malicious smile on her face. Rose had always wondered how people could be surprised as totally evil. When they'd met Margaret the Slitheen for the second time in Cardiff she had proved that she wasn't totally evil. But the woman looking at Rose now didn't have a single good bone in her body.
How could she take an innocent child and simply kill it? It was one of the things you just didn't do. The only people who killed innocent children were terrorists and murderers, not heads of secret organisations in charge of keeping aliens secret from the public.
Rose felt the Doctor take her hand, but somehow it was like it was happening to a different person. All she could think of was Jack lying sick in the TARDIS.
"Where's the cure?" The Doctor asked after several minutes. Yvonne's smile widened.
"Wouldn't you like to know?" She said almost gleefully.
That's why I asked," he said quietly.
"I'm hardly going to tell you am I Doctor?" Yvonne said. Rose couldn't take it any more; she launched herself at Yvonne and started laying into any part she could reach. Punching, kicking, scratching, tears rolled down her face as she thought that her son might die.
The guards couldn't pull her off; it wasn't until the Doctor grabbed Rose's arms and pulled her up that she relented. She sobbed into his shoulder arms wrapped round him as the guards helped Yvonne up, shaken and bleeding.
"Big mistake, Rose," Yvonne hissed. "If you had any chance of getting the cure you most certainly don't now."
The Doctor backed into the TARDIS, pulling Rose with him. Yvonne was still staring at him as he shut the doors, glaring at him as though she'd like nothing more than to put him through another regeneration.
"She… she…" Rose tried to speak but her sobs prevented her.
"I know," the Doctor replied pulling her into another hug. "But at least we know there is a cure."
"My baby can't die," Rose said pulling back to look at the Doctor, fear etched across her face.
"Rose, he's my son too, I know exactly what you're feeling," the Doctor said, cupping her cheek with one hand. "I will do everything in my power to keep him alive. For all we know, the illness might not kill him. If Jack's the test then they might not have it perfected to Time Lord Standards."
Rose nodded sadly.
"Will… will it be passed on to anyone who comes into contact with him?" Rose asked.
"I don't know," the Doctor said quietly. "Do you feel ill?"
Rose paused for a moment to think about it and shook her head.
"Nope, me neither," he continued. Jack came running into the console room, stopping when he saw the Doctor and Rose were stood by the console.
"Jack's getting worse," he said quickly, before leading them back to the infirmary where Jack lay, shaking, cold sweat pouring over his body.
Rose rushed over to scoop him up into her arms whilst the Doctor ran over to the computer and began tapping at the keys. Jack and Charlie stood back unsure of whether to leave or not.