"There is no chance, no destiny, no fate, that can circumvent or hinder or control the firm resolve of a determined soul." Ella Wheeler Wilcox

The detector went off in the middle of the night. The soft but insistent beeping roused him from sleep, and it took him only a moment to realise what it meant. The Doctor sat bolt upright in bed, reached for the detector blinking and beeping on his nightstand, and felt his single heart beating rapidly in his chest. Rose turned over next to him, mumbling something.

"Rose," he said in an urgent whisper, reaching over to jog her shoulder a little. "Wake up."

"It's too early," she mumbled into the pillow. "And what's that beeping?"

"It's happened."

She rolled over and blinked at him sleepily, wincing when he switched on the lamp. "What has?"

"The walls are opening."

Her eyes flew open wide and she sat up, grabbing his arm. "You mean?"

He swung his legs over the side of the bed and stood. He pressed a switch to silence the beeping, although the lights still blinked at him, nearly in time with his heart. "I have to go."

She slid out of bed and into her dressing gown, belting it roughly around her waist. "Hold on, we've talked about this."

"Yes, we have. I have to go." He dressed quickly as she watched, her arms folded across her chest.

"I'm coming with you."

He opened the drawer and pulled out the vortex manipulator he had made from salvage parts – which included a modified dimension cannon - and the sonic screwdriver he had cobbled together. "No, it's not safe."

"Then you aren't going either." She stepped in front of him, her mouth set in a firm line.

He strapped the manipulator to his wrist and tucked the screwdriver into his pocket, along with the other things he needed. "I have to. Donna's in danger, and I can't leave her like that."

"He will have figured out something."

The other Doctor. The man he was and yet wasn't. "No, he won't have."

"How do you know? You have his mind, don't you? He would know what you know."

He sighed, taking her shoulders in his hands. "Yes, but I also have her in my head. And that little bit of human makes me think...differently."

"Hm," she said, but she stepped into his arms. "You can save her?"

He closed his eyes as he embraced her. Yes. No. Maybe. "I don't know. But I have to try."

She nodded against him and her arms tightened briefly around his waist before she stepped back. "Go. Hurry. But come back to me."

He kissed her quickly, smoothing her hair back. "I'll try. I don't know how long the window will be open." At her look he added. "I'll try, I promise."

***

Donna stared in horror as Shaun and her mother began shaking their head wildly, their features finally resolving into the same face – a man. She clutched her mobile to her ear, her grandfather's voice the only normal thing in a world that seemed to have gone mad. "But they've changed!" Her temples throbbed as memories began to surface. "Granddad, it's like – like the sort of thing that happened – before!" she cried with a sob, backing away from the strange, menacing figures. Images flashed through her head, unconnected, strange yet familiar. A giant spider, a giant wasp, giant creatures that seemed to be made of rock.

She crumpled against the wall, clutching her head as pain flared through it. ""My head! Oh, my head. Oh, my head!"

She squeezed her eyes shut and pressed the heel of her hand against her temple, struggling for breath. Suddenly the images were gone, replaced by the sound of a heartbeat. She knew it wasn't her own because she could feel hear heart pounding far too fast in her chest. As the sound grew louder in her head, the pain eased, then disappeared along with the noise. She opened her eyes in time to see the strange men who had replaced Shaun and her mother take a step toward her, smiling menacingly.

She had to get out, she knew, and she turned and ran out of the house into the lane, crouching by the wall. "Granddad?" she whispered into the phone, but the line had gone dead. She redialled, her hands shaking, and she held her breath as she waited for him to answer. Finally there was a faint click on the line, and the ringing stopped. Tears of relief stung her eyes. "Gramps, don't hang up, you've gotta help me! I ran out! Everyone was changing!"

She could hear voices, faintly, over the phone, and she pressed it harder to her ear. "Gramps, I can't hear you." She paused, listening again, and again heard voices faintly in the background. Pain throbbed in her temples again. "Are you there? Can you still hear me?"

"Donna, get out of there!" A mixture of panic and relief filled her at the sound of his voice. She choked back a sob as she started to run, looking wildly up and down the alley, only to see more of the strange, menacing men, all identical, begin to approach her. She could hear her grandfather shouting at her to run.

"What do I do?" she asked, panicked. She couldn't think through the throbbing in her temples, and that strange sound, like a heartbeat, sounded in her ears again, almost drowning out her grandfather's voice.

" Run, sweetheart! That's all! Run for your life!"

" There's more of them," she said, as they began approaching her in the alley. "They're everywhere!"

One of the men said, "Ooh, I'm starving!" and a wave of fear washed over her. She could feel her heart beating as the pain intensified in her head. The strange heartbeat that wasn't hers continued, growing louder as images flashed once more through her mind.

She pressed her hand to her head as she whispered into the mobile. "I can see those things again. Those creatures!" She fought back a wave of hysteria as she cried, "Why can I see a giant wasp?!" Her head felt hot, and the pressure kept building as the images continued. She saw a man, looking down at her, so familiar, and the pressure became unbearable. The heartbeat in her ears stopped as suddenly as it had started, as her head snapped back and she saw a wave of golden energy pass through her and out of her, and everything went black.

***

He landed hard on a street in Chiswick, and struggled to catch his breath as he quickly checked the vortex manipulator on his wrist. He sighed in relief as he realised it had worked – he was back on Earth, in his "home" universe. He carefully closed the cover of the manipulator, hoping it still had enough energy to return him before the walls closed again. He looked around quickly, trying to get his bearings. The street was deserted, and he was grateful for that. His appearing out of thin air might have made him noticeable. He saw movement behind a curtain, and jogged quickly down the street toward the Noble's house. He hoped that's where he would find her.

He heard her before he saw her, and fear shot through him at the sound of her crying out, "Why can I see a giant wasp?" He sped up, fearful that he was too late, she had already remembered too much. He turned the corner just in time to see the golden light flow from her and knock down the men that had been surrounding her.

"Donna!" he called, as she crumpled to the ground. He ran, only briefly glancing at the men who had fallen around her. He would worry about who they were later. He knelt beside her and pulled her into his lap, smoothing her hair back from her face. Her mobile fell to the ground with a clatter, but he hardly noticed. What had the Doctor done to her? "Donna?" he said softly.

She moaned softly, but didn't open her eyes. Frantic, he pulled out the sonic screwdriver and scanned her quickly. He sighed in relief after he studied the readings, and smiled to himself. The Doctor had been more clever than he had thought – he had left her with a safety valve to bleed off the metacrisis energy. It was good – it would protect her from the memories, and keep her safe from anyone trying to access the information, but he could do better, he knew.

He stood, then bent to scoop her into his arms carefully. He carried her back into her house and laid her gently on the sofa. He quickly checked the rest of the house, and was relieved to find it empty. He drew the curtains and locked the doors, and returned to her side. "Alright, Donna, let's see what we can do," he muttered, as he set to work. The coffee table was soon covered with the bits and bobs of tech he had brought with him, but he worked quickly to assemble everything. He didn't know how long he had until the walls closed again.

***

She felt cool hands against her face, and something cold and metallic pressing against her temples. She lifted a hand weakly to try to touch whatever it was, but the hands stopped her. "Donna, can you hear me?"

She opened her eyes slowly, struggling to focus on the face swimming in front of her. Her breath caught as she realised who it was. "Doctor?" she asked, surprised at how faint her voice sounded.

He shook his head. "Not exactly," he said with a grin. He took her hand and pressed it to his chest, over his single heart.

"Oh, it's you!" She tried to sit up but he pressed her shoulders down gently.

"Just wait, give me a minute here." He pressed his hands to whatever was attached to her temples, and the metal released. He lifted the strange device and set it gently on the table. "There we are." He pointed the sonic screwdriver at her and scanned her.

"You made a sonic?" she asked.

He nodded. "Among other things. I think that's done it. How do you feel?"

She considered for a moment. "Fine, I think. What happened?" She sat up, and this time he helped her, shifting the pillow behind her to help her sit up.

"What do you remember?"

"Well, you to start with. Hang on, I shouldn't, should I? He took all the memories – everything! I was burning up..."

He nodded. "Yes, you were. There was nothing he could do, he had to save you."

"I begged him not to..." she said in a whisper. "I couldn't go back."

"He couldn't let you die," he said simply, taking her hand. "I'm sorry, there's not much time to explain."

"Why don't you start with how you got here. You shouldn't be here at all."

He shrugged. "More than one impossible thing will happen today." At her frown, he added, "Yes, I'll explain it all, but perhaps we should start with the men in the lane?"

She sat up, her eyes wide. "Oh – we're not safe here!" She stood quickly and swayed a little on her feet, and he jumped up to grab her.

"Easy there," he said, slipping an arm around her shoulders. "Who are they?"

She shook her head slightly. "I don't know! I was in the kitchen, with Mum and Shaun, and –they changed, right in front of me. And they were everywhere, these men – all alike!"

"Okay, let me just have a look," he said, hurrying to the window. She followed him and they peered out into the street, where the men were still unconscious.

"Did I do that?" she asked, turning to him.

He didn't answer, just kept staring out at the men.

"Doctor?"

He turned to her then, his eyes distant. "Like I said, more than one impossible thing will happen today. I thought the readings were wrong—"

"What readings? What are you talking about?" She hated to hear the panic at the edges of her own voice, and she reached for his hand to steady her. He squeezed it, and looked at her properly.

"Of course. I think we're safe in here for now," he said, but he released her and hurried to lock the doors. She returned to the sofa and sat down, feeling suddenly tired. She rested her head in her hands for a moment, trying to remember. She remembered being in the lane, and her head feeling so hot and full, full of the sound of a heartbeat, and a bright light, but then nothing. And who were the men? What about her mother? And Shaun?

The other Doctor returned and sat next to her, and she looked up at him. "Does she call you Doctor?"

"Who?" he asked, surprised.

"Rose. Or did you choose another name?"

"I'm the Doctor," he said simply. "I don't know what other name I would choose."

She nodded, understanding. How could he choose another name? "Alright then, Spaceman, you said we didn't have much time."

"And we don't, so you'll have to trust me on some things."

"Okay."

He took a deep breath and let it out slowly, and she could almost hear him thinking. "You know that the parallel world runs a little ahead of this one, right?"

She nodded. "Right, I remember that."

"Well, not long ago we started getting strange readings, things that shouldn't be happening. At first I thought the equipment was faulty, because nothing made any sense, but I eventually realised what was happening."

"And what was that?"

"The connection between the universes was opening again."

"But the Doctor said that was impossible – that they would stay closed this time, forever."

"It won't be the only thing he was wrong about, either. But only because something is happening, or will shortly happen, that makes travel between the universes possible again. Something he would never have let himself imagine would happen."

She tilted her head at him. "What's that?" she asked, a strange dread filling her at the thought of what that might be.

"Gallifrey is returning," he said simply, and she felt cold at the thought.

"And that's not good."

He shook his head. "Not the Gallifrey that is returning, no. The Gallifrey that was trapped in the timelock, forever fighting the Time War is returning, where they've all gone mad."

She heard a sudden commotion out in the street, a cacophony of voices, and she flinched. Were the men coming back for her?

He rose quickly and hurried to the window, peering out through the curtains. "Whatever changed everyone seems to have been reversed," he said, turning to her. "Everyone's back."

Relief flooded through her – her mum would be okay, she hoped. But, Gallifrey? She bit back a thousand questions, knowing there wasn't much time. "But, how could it return?"

He returned to sit next to her again. "I don't know. The Doctor, your Doctor, will have to tell you. All I know is that their return opened the walls between the universes again, rippling back enough for me to find you."

"You came back – for me?"

He nodded. "Of course. I knew what had happened – or guessed, anyway. And I couldn't let you stay here like that. It's too dangerous, and his solution was only temporary. I figured out a way to give you your own memories back, and protect you from the metacrisis."

She glanced at the coffee table, at the strange contraption he had left there. "How did it work?"

He grasped her shoulders, his eyes intense. "It's not important right now. He'll figure it out and explain it to you later. Right now, you need to find him and stop him from doing something."

"Stop him? From what?" She felt cold fear in the pit of her stomach at the expression on his face.

"He will sacrifice himself, but it will kill him, and you need to show him there's another way."

"But – he'll regenerate, right? He'll be okay?" Her voice cracked. What if she couldn't stop him? He couldn't die, not now that she remembered him, and everything they had done. What if she wasn't fast enough?

"Yes, but that's the thing – he doesn't have to. There's another way, and he can avoid regenerating. The timelines are still in flux from--" he hesitated. "Something that happened. That's for him to explain if he wants to. He needs you, now more than ever."

She gasped as the ground began shaking under them, and pictures began falling from the wall.

"It's started," he shouted over the noise, and pulled her into the doorway. She heard more shouting out in the street – men's and women's voices raised in panic. She wondered where her mother and Shaun were – probably out looking for her.

She took a deep breath and braced herself against the door frame. "Tell me what I need to do."

"And you're sure that will work?" Donna watched the other Doctor's face closely.

"Not sure, no. But I believe it will save them both, without forcing him to regenerate, or risking anyone else."

She took a deep breath. "Okay. I just need to get to the mansion."

"There's no time for that."

"What then?" she asked, fighting to keep the panic from her voice. The Doctor and her grandfather were out there, in terrible danger, and she was stuck here, helpless.

He picked up her mobile from where he had left it on the table. "Call your grandfather."

One of the pieces of machinery the Doctor had brought with him began beeping, and he glanced quickly at the vortex manipulator on his wrist. "The walls are closing. I have to go."

"You can't stay?" she asked, although she knew the answer. I heard your heartbeat, she thought.

"No. Even if I could –" he smiled at her and took her hand. "Rose is there, waiting for me. I promised I'd go back to her." The beeping noise became louder, more insistent. "There's not much time. Call him. He needs you." He stood and flipped open the cover on the manipulator.

She stood and hugged him quickly. "Thank you. For everything." For giving me my life back, she thought.

"Thank you, Donna Noble," he replied. "For everything." He flipped a switch and disappeared.

She fought back tears, trying to focus on what needed to be done.

***

The Doctor rolled to his knees with a groan, the broken glass crunching beneath him. He blinked in the sudden silence - the light and sound from the Gate now gone. Every bone, every muscle ached as he struggled to his hands and knees.

"I'm alive," he said, hardly believing it. Relief rushed through him, overcoming the pain from the cuts and bruises caused by his fall through the skylight. "I'm alive!"

The silence was broken then, by the unmistakeable sound of someone knocking on glass. Four sharp taps, a pause, then repeated. His hearts sank as he realised who was knocking, and what it meant. Wilfred. He had tried to stop him before he got himself trapped in that glass box, but he had been too late. And in through the confusion following, he had remained, trapped. He sat back on his knees and looked over at him. He will knock four times…

"They've gone, then. Good-oh. If you could let me out?" Wilf asked.

"Yeah," he replied. How could he not?

"This thing seems to be making a bit of a noise."

He struggled to his feet, trying to ignore the pain. The control booth was making unsettling sorts of noises, and he could see alarm lights flashing on the panels. He knew without really looking what had happened, and what it meant. "The Master. He left the nuclear bolt running. It's gone into overload."

"And that's bad, is it?"

"No. 'Cos all the excess radiation gets vented inside there." He nodded at the glass enclosure Wilf stood inside. "Vinvocci glass. Contains it. All 500,000 rads about to flood that thing."

"Better let me out, then."

Oh, if only it were that simple, he thought. "Except it's gone critical. Touch one control. It floods." He will knock four times. And then you'll die.

He started to reach into his pocket for his sonic screwdriver, even knowing it would be useless, when he was startled by the sound of a mobile phone ringing. He looked up at Wilf, half afraid that the signal would have set off the radiation venting, and was relieved when it didn't. He fumbled in his pockets for the source of the sound, and finally pulled out Martha's mobile phone, the one she had left on the TARDIS for him.

He glanced at the display, and his hands trembled at the words on the screen. "Donna calling," it read. He looked up at Wilf. "It's Donna," he said, simply.

"But, how? How could she—"

"You said she was remembering."

"And you said she would be okay!" Wilf cried. He pressed his hands to the glass, helpless. "Are you going to answer it?"

The Doctor hesitated. If she remembered this number, she must surely have remembered more. He had to know. He pressed the button and held the phone to his ear, unable to speak.

"Doctor?" Donna's voice was as clear as if she were in the room with him, and he closed his eyes at the sound.

He swallowed hard. "Yeah."

"Oh, thank God," she said, and he could hear the fear in her voice. "Is Gramps still there?"

He looked over at Wilf. "Yeah, he's here."

"Good. Now, there's not much time, I need you to listen to me."

His mind whirled with questions. "How did you know how to reach me?"

He heard her sigh impatiently. "He came back, and did something so I can remember you without burning up."

"Who did?" Happiness warred with despair inside him – she remembered him, all they did, but too late. He would die, here, without her.

"The other Doctor. He said the walls opened, he saw it before it happened. And he told me what you need to do."

Gallifrey's return, he thought. It allowed the other Doctor to travel back here. "I know what I need to do. There was a prophecy—"

"No," she said, surprising him with the strength of her response. "When did you start believing in prophecy?"

When I had to leave you, he thought. He said, "I was told I would die."

"Not today," she said firmly. "The prophecy was wrong. Now, listen to me closely. You only have a few minutes, but you need to bypass the door protocol controls and let Gramps out, but trick the system into venting into the other cubicle. Can you do that?"

"Who told you that?"

"He did," she said, impatiently. "He made me memorize it. Can you do it?"

"I don't know. Anything could set it off—"

"Doctor, listen. I believe in you. If anyone can do it, you can." She paused. "Please. I only just remembered you."

He looked at Wilf, who was watching him, silent. Hope welled within him for the first time since he had left her, since he had heard the prophecy, since Mars. "Alright." His mind was already buzzing with an idea of how to make it work, to save them both. "I have to put the phone down."

"Do what you have to do," she said. "Just, please, come back." He could hear the raw emotion in her voice, the barely suppressed panic.

"We'll be right there," he said. He slipped the phone back into his pocket and removed the sonic screwdriver. He looked up at Wilf. "Wish me luck?"

***

She stood in the kitchen, clutching the silent mobile, praying to whatever gods would listen that this would work, that he could pull off this impossible task. The minutes seemed like hours as she waited, refusing to give up hope. Finally, she heard it – the familiar sounds of the TARDIS. Tears started in her eyes as she dashed out the door to see the familiar blue box sitting in their back garden. She stopped, and watched as the door opened, revealing first Wilf, and then the Doctor. She ran and embraced her grandfather. He hugged her back quickly, then released her. She could see tears shining in his eyes.

"You alright?" she asked him softly.

He nodded. "I'm fine, thanks to you and the Doctor."

She looked up at the Doctor, standing awkwardly behind Wilf, watching her intently. She reached out and took his hand, suddenly shy. "You came back."

He drew her closer. "I couldn't leave you again."

She nodded, swallowing hard against a lump in her throat. He pulled her into a hug, and she relaxed against him for a moment, before pulling away slightly. She touched the cuts on his face. "What happened?"

"That is a very long story, and one I'll be happy to tell you later," he said, capturing her hand in his again and pressing it to his chest. He looked over her shoulder. "After we deal with your mother."

"Oh, Mum!" Donna said, turning from him to see her mother emerging from the house, Shaun close behind.

"Donna? What are you doing? You can't—" Sylvia stopped and stared, clearly horrified.

Wilf intercepted her. "It's alright, darling, she remembers. It's safe, she's fine."

"Oh God, Shaun," Donna said softly, turning back to the Doctor. .

"It's okay, your grandfather told me," he said quietly. "If you want to stay—"

She shook her head. "No, you're not getting rid of me again. I just—need a minute, okay?"

He squeezed her hand. "Take as long as you need. I'll be here."

"Thank you." She turned and walked to Shaun, who was looking completely bewildered. She took Shaun's hand. "Walk with me."

***

She sat next to Shaun in the front garden, watching the range of emotions play across his face as she explained.

He shook his head. "Your mother said that you could never remember."

She sighed. She was furious with her mother for telling him. All this time, they had been talking behind her back. She understood why, of course, but it didn't make it any less frustrating. "That's what everyone thought. It turned out to not be true. I'm sorry."

He took her hand again. "You're going with him."

"Yeah."

"I can't talk you into staying?"

She smiled, sadly. "You weren't in love with me. Not the real me, the whole me."

"That's not true. I love you, just as you are, no matter what."

She leaned over and kissed his cheek. "I know, and I'm sorry. I can't stay, not now that I remember what's out there, what else there is to do. I'll come back and visit. It's a time machine, remember?"

"It might be easier if you don't," he said, releasing her hand and standing. "You belong with him, and I won't be the one to keep you here." He helped her up.

She looked down at the engagement ring on her finger. She removed it, sliding it easily over her knuckle, and pressed it into his palm, folding his fingers over it. "You'll find someone," she said, blinking back tears. "Someone who won't leave you."

She turned and went into the house, grateful when he didn't try to call her back. She quickly gathered up the gadgetry the human Doctor had left behind, and shoved it into a bag with some of her clothes. She couldn't resist peeking out into the back garden, reassured when she saw the TARDIS still there, the Doctor nowhere in sight. Inside, probably, she thought. Tinkering. She packed quickly.

***

The TARDIS doors opened at her touch, and she smiled as she felt the ship's familiar presence envelop her as she stepped through. The familiar hum, the sights and smells of the TARDIS greeted her, as though she had never left. He turned quickly from where he was bent over the console, and she walked quickly up the ramp to where he stood.

"I missed you," he said, after a long silence.

"I missed you, too," she replied. "I didn't remember you, but I knew something was missing."

He nodded. "I'm so sorry – I had to—"

She reached for his hand quickly. "I know. He explained it to me. You did what you had to."

"How did he know how to save you?"

She shrugged. "He didn't explain it, there wasn't time."

He smiled. "I think it was you. The part of you left inside him, told him what to do."

"Perhaps."

"When we first met, you said I needed someone."

"Yeah. I was right, too," she said, trying to keep her tone light. He looked older, beyond the bruises and cuts that still marred his face. He looked tired.

"Yes and no. I think I needed you." He dropped his chin to his chest, and she could hear the emotion in his voice, barely suppressed. "I did some things, while you were gone..."

She stepped closer, rested her hand over one of his hearts. "It's okay. I'm here now. We'll fix things. Together."

He looked up at her and nodded, silent as he tried to compose himself. Finally he smiled and met her eyes again. "Onwards?"

"Onwards," she replied, with a smile, as she stepped into his arms. She was home.