Rose wasn't surprised when the Doctor insisted they visit the med bay immediately after breakfast on her first morning home. She still hadn't told him about the dimension cannon, but obviously, she'd crossed the Void to get home, and she'd been through enough post-jump physicals to know that carried a certain amount of risk.
"What about Donna?" she said, hoping to put off the exam and explanation for a little bit longer. "We were supposed to go get her this morning."
The Doctor raised an eyebrow. "We can go into the Vortex and take all the time we need on your physical, then land back on Legilo and pick Donna up."
Rose nodded reluctantly and followed him to the console room. When the TARDIS shifted into the Vortex and away from the telepathic dampening field of Legilo, the full return of her telepathy made her dizzy, and she grabbed onto the railing.
"Rose?" The Doctor was at her side in an instant. "What's wrong, love?"
She reached for his arms instead of the railing and looked into his eyes. "Nothing," she gasped, blinking back tears. "I just… I forgot…"
The furrow between his brows smoothed out. "Oh," he breathed. "You're back." He put his hands on her waist and slid them up under the hem of her shirt, until his palms were pressed against her bare back. "Oh, Rose."
Rose tilted her head back, and that was the only invitation the Doctor needed. He swooped down for a kiss, catching her bottom lip between his and nipping at it lightly before running his tongue over it. Her hands glided over his shoulders to sink into his hair, and she felt his moan against her lips before his tongue swept into her mouth.
Doctor, she sighed. Oh God, I missed you. So much. The last remnant of her headache finally eased away, and the sudden relief after five years of constant pain was almost orgasmic. One of his hands left her back and cradled her neck at the base of her skull, massaging the previously-aching spot gently, and she shuddered in delight.
The telepathic ties of their bond tightened and strengthened around them, until it almost felt like they were one person. Their emotions were shared—joy, relief, love, desire…
Fear?
Rose eased out of the kiss when she detected that jarring note. The Doctor followed her, catching her lips in another kiss, and she used their bond to point out his fear. He sighed, but let the kiss end.
"Right. We were going to the med bay," he said, his voice rougher than usual. "And then once we're done with the scans, we can revisit this."
Rose smiled and took his hand. "I approve of that plan," she told him as they started down the corridor.
"Tell me about the dimension cannon," he requested when they entered the med bay.
Rose hopped up on the examination table and lay down while the Doctor turned on the scanner. "I told you on that beach that I was looking for a way to come home," she began once she was comfortable. "I was already working on my A-levels, and when I was done, I had one of Torchwood's scientists tutor me in quantum physics." She laughed and shook her head. "You'd like Malcolm, Doctor—he's a proper genius."
The Doctor ran the sonic over her body in long, sweeping passes. "Maybe we'll run into his counterpart in this universe one day."
Rose focused on his eyes so she wouldn't following the blinking diode of the sonic screwdriver. "That'd be nice."
She took a deep breath; the next part wouldn't make him happy. "Anyway, we still had the hoppers, and after taking them apart to figure out how they worked, we built this thing, this dimension cannon, that was supposed to send me through the Void to another universe."
He pressed his lips together in a thin line. "You were supposed to get rid of those things."
Rose attempted a cheeky smile. "You never actually said that." The Doctor didn't laugh, and she sighed. "Look, if we hadn't used the hoppers, it would have been decades before we developed the technology to go between dimensions. I'm here because we used all the resources we had—including the hoppers. Would you rather I weren't here?"
"No!" The denial leapt to his tongue as a visceral recoil swept through the Doctor. Having Rose here was everything he'd wanted for three years.
He sighed and rubbed at his eyebrow, letting the strength of his reaction fade. "No, of course not, but…" He shook his head and pressed the button on the sonic, sending the information through to the waiting computer. "Here, sit up."
Rose swung her body around so she was sitting up with her legs dangling over the side of the bed. The Doctor sat down beside her and took her hand. As always, the skin-on-skin contact intensified the already deep connection between them, and he could sense the nuances of her frustration.
"I'm sorry," he said quietly. "I just can't ignore how much danger you put yourself in, and it scares me. Because you're here now, but what if the way you got home ends up making you sick?" He drew a shaky breath. "I can't lose you again, love."
His fear mingled with her frustration, and then washed it away as she understood his reaction better. A moment later, Rose rested her head on his shoulder and ran her free hand over his arm. "We did everything we could to make it safe, both for the universe and for me," she told him. "The dimension cannon opens a wormhole that only oscillates at a rate of five Malcolms per second. That means it's extremely narrow, only allowing for the travel of one person in one direction. But it's still fast enough to close itself as soon as transit is complete."
Five Malcolms… The Doctor twisted his neck so he could look down at Rose, a smile stretching across his face. "Did your friend name a unit of measure after himself?"
Rose laughed. "He did, yeah. But he discovered it, so I guess that's his right. A wavelength parcel of ten kilohertz operating in four dimensions equals one Malcolm."
The Doctor whistled. For a human to measure something in four dimensions… A proper genius indeed. He did the calculations in his head and nodded; five Malcolms per second would create the force necessary to penetrate dimension walls.
"So, the dimension cannon was supposed to send you across the Void?" he said, bringing them back to where his fear had derailed the conversation.
"Oh, right." Rose straightened up and continued her story. "It didn't work. Malcolm and I couldn't figure out why. All the calculations were correct. And then the stars started going out."
"What?" Of all the things she could have said, that was not even close to what he had expected.
Rose turned to look at him, and the merry twinkle in her eyes had faded to sober determination. "Yeah. I'm actually here on an official mission from Torchwood. About ten months ago, the stars started going out. Not long after, the readings from the dimension cannon changed. It started picking up radio signals from other universes, and then letting us do do basic scans to check the atmosphere on the other side. And then, one day… the cannon worked. I went through the Void to another world and came back ten minutes later."
But that means… "You mean reality itself started to break down, and that made the walls between the worlds porous," the Doctor said slowly.
Rose nodded. "That's what Malcolm reckoned, too. Even the Void is dying, Doctor. The first few hops I took, I could… well, I could sort of feel it around me? The nothingness, I mean. Passing through it felt like going through treacle. But after a month, it got easier. And now… now it's like teleporting."
The computer beeped, interrupting the thoughts whirling through the Doctor's mind. If reality was breaking down, then an end-of-the-universe crisis was looming… but for the moment, Rose's health and safety were his priority.
"We'll talk more about the stars going out later," he promised as he stood up.
She rolled her eyes fondly. "Go on, check the tests. And when you have proof that I'm just fine, we can pick Donna up and I can tell both of you what I know."
The Doctor nodded absently; his focus had already shifted to the charts and numbers filling up the monitor. He frowned when he recognised the form the TARDIS had dropped the data into—this was the one he used for his own medical tests, not for his human companions.
"What are you up to?" he muttered, smacking the side of the monitor.
He heard the sound of fabric against fabric as Rose slid off the exam table. Then a moment later, she was at his side, peering at the monitor with him.
"What's wrong?"
"I don't know." He typed in the command that would transfer the information to the proper form, but the TARDIS whistled sharply in his head.
Rose winced at the sound of the TARDIS' annoyance. "What was that?" she asked, rubbing her temple.
"I don't know," the Doctor repeated. "But she refuses to transfer your scan results to the human form, so we might as well read them here."
Rose turned and leaned against the nearby counter so she could watch his reactions. The medical results were beyond her understanding anyway, and she would learn more by watching the shifting expressions on his face. Gradually, his irritation was replaced by confusion, and she turned just enough to be able to also see whatever was on the screen.
The Doctor's eyes were wide, and Rose looked from him to the results and back at him again. A deep furrow in his brow went along with the sharp tone in his voice when he asked, "What?" He shook his head. "That can't…" He tapped in a command, and another image popped up. "I'm sorry… what?"
"What is it?" Rose asked. She knew he wasn't scared, just very confused.
The Doctor took a deep breath and turned the monitor so she was looking at it straight on. As he did, the text on the screen was replaced by a diagram of three strands twisting together. There was something familiar about the image, but it was off by just enough that Rose couldn't pinpoint what it was.
"What is it?"
He ran a hand through his hair. So far, the only emotion she'd been able to pick up from him was shock.
"It's… That's your DNA, Rose."
Rose frowned at the screen and shook her head. That was why it had looked familiar, she realised now, but… "DNA has two strands," she said. "It's a double helix."
Some of the Doctor's shock was fading, and Rose felt a hint of excitement coming through. "Human DNA, yes. But Time Lord DNA is a triple helix."
Rose looked at the image, then at her husband, bouncing lightly on his toes while he waited for her to put the pieces together. He was practically vibrating with excitement now, and she let the obvious solution sink into her mind.
"I'm a Time Lord," she said slowly. "Because… Because of what I did as Bad Wolf? That made me like you?"
The Doctor giggled and picked her up and spun her around. "Yes!" he crowed. "Oh, my beautiful, brilliant Rose. Do you know what this means, love?"
He set her down, but kept his hands on her waist, and Rose looked into his sparkling eyes. The shadow that had lingered there, even in their happiest moments, was gone completely.
"It means we can share our forever," she breathed, swaying on her feet as the truth hit home. "If I'm a Time Lord, I'll be able to regenerate. You won't have to be alone again."
As she spoke the words, a golden memory unlocked in her mind. "I did this," she whispered. "I saw your future, so alone… and I said no. So I reached out with the Time Vortex, and I changed my own body so I could be with you forever."
The Doctor's breath caught in his throat and he pulled Rose into a hug with his arms wrapped tight around her waist. "Oh Rose," he said into her hair.
Rose turned her head and kissed his jaw. "I want you safe, my Doctor," she told him. "Safe and happy, for as long as you live."
She carefully disentangled herself from him and pulled gently on his arm, tugging him towards the monitor. "So, can you tell me about the new me?" she asked. "What should I expect? Super-human strength? A superior biology?"
The Doctor stuck his tongue out at her gibe. "As a matter of fact, yes," he said. "And you'll soon discover I'm not just making things up when I say that."
Rose frowned; another fact had just slipped into place. "I think I already have, kinda," she said. "I've been sleeping less, and I heal much faster. It always amazed them in my post-jump physicals how few side effects I experienced from going through the Void."
The Doctor nodded. "Time Lords are pan dimensional," he explained. "We're made to travel from universe to universe. That's why we only exist here, in the prime universe." He tilted his head and rested his tongue on his teeth. "I should have wondered when there wasn't a Rose in Pete's World," he realised.
Rose pushed a reminder over the bond, and the Doctor jumped slightly. "Oh! But you wanted a quick tutorial on your new body." He closed the diagram of her DNA and went back to the top of the report, pointing out the important things like respiratory bypass and the enlarged frontal lobe of her brain that made telepathy possible for Rose.
When they got to the last paragraph, Rose could tell whatever it said was almost as surprising to the Doctor as the news of her genetic transformation. He looked up at the ceiling through half-closed eyes, his mind whirling with some kind of calculation.
"Right," he muttered as he spun away from the monitor. "Well, that's easy enough to take care of."
Rose frowned when he opened a drawer and dug through its contents, pulling several bottles out and setting them on the counter. He started mixing something, muttering to himself as he went along like he was creating a potion.
"Not a potion," he said absently. "Birth control."
Rose's jaw dropped, but it only took a moment for her to fit the puzzle pieces together. They'd never used birth control, because humans and Time Lords weren't genetically compatible enough for natural conception. But if her DNA had changed to match his, she could get pregnant.
"Exactly," the Doctor said. He carefully put his formula in a test tube and put it in a centrifuge. "So I'll just take this birth control, and we'll be taken care of."
Rose looked at the machine, then at the Doctor. They'd never even talked about kids, except the one conversation where he'd told her they weren't possible. And now he was just… She clenched her hands so tightly she could feel her nails digging into her palms.
"Rose?" the Doctor said carefully. The anger and hurt pouring off her were strong enough to give him a slight headache, and he turned away from the machine to look directly at her. "Have I done something wrong?"
She snorted. "Well, usually a couple talks about kids together," she pointed out, her voice sharp. "Before one of them opts for permanent birth control."
The Doctor blinked, then shook his head. "But you… I didn't think you wanted kids," he said, stammering just a little. "You've never mentioned…" He let the words trail off and shoved his hands into his pockets.
Rose sighed, and some of her anger eased. "Well, I hadn't really thought about it before we met," she admitted. "I was only nineteen, after all—settling down with a husband and kids was still several years out, if I thought about it at all." She crossed her arms over her chest and looked up at him. "And then I fell in love with an alien," she said pointedly. "Not much point thinking about something you know you can't have."
The Doctor studied his wife carefully. "Rose… do you want to have a family?"
"We're already a family, Doctor," she corrected.
He nodded impatiently. "Right, but would you want a baby? Or maybe… a few children?" he asked.
The Doctor tried to keep his imagination under control while he waited for her answer, but he couldn't stop himself from picturing a little girl with Rose's cheeky smile, laughing as he spun her around. His hearts ached when the childish voice called him Daddy, and despite himself, he wished fervently that the vision might be his time senses giving him a glimpse of the future, and not just his over-active imagination.
"Oh!" Rose's eyes widened. "You want kids. You really want kids. Why didn't you ever say?"
The scene in his mind's eyes faded away, and the Doctor focused on his wife. Rose had her hands knotted together the way she did when she felt uncertain about something, and he reached for them, gently untangling her fingers and lacing them through his own.
"Because I don't want them if you don't," he told her seriously. "So please don't feel like you have to agree to have a baby now, just because it's possible and you know it's something I want."
Rose bit her lip. "Can I… Can I have some time to think about it?" she requested. "Because I've never even thought about if I wanted to be a mum, and now…" She shrugged. "Even if I do decide I want to have a baby, I think I want a little time alone with you first. Plus, it's not exactly the best time to get pregnant, when we're in the middle of a universe-threatening crisis."
"Right, the stars," the Doctor remembered. He smiled at Rose. "You can have all the time you want, love. You were right that this birth control I was formulating would have been permanent, but there's a shot I can give myself that'll last for three months. And if you're not sure then…"
Rose nodded, and he knew she understood that he would give her all the time she needed. She stretched up onto her toes and brushed a kiss over his cheek. "Thank you, Doctor."