Pulling her coat around herself to ward off the chill of the autumn evening, Donna wasn't sure why she was out here at all. Normally at this time of night, she'd have tucked Peter into bed and flopped onto the couch to watch her celebrity programmes and gossip on the phone, but tonight, she really felt like taking a walk. Maybe she just wanted to get away from everyone. Between working a full-time job, being a mother, and keeping up with the girls, she rarely had any time to herself. Tonight, the idea of darkness and some blessed silence just sounded so good! She'd brought her mobile, of course - a six-months pregnant woman walking alone at night, she wasn't totally bonkers - but she'd put the ringer on silent and had already ignored two calls, probably both from Veena. She was alone with her thoughts, wandering the dark Chiswick streets.

Cars with blazing headlights rumbled down the road and pedestrians heading to pubs and nightlife strolled past her, and she grinned, reliving old memories of heading out, night after night, with the girls when she was younger. Nostalgia was certainly fun, but it glossed over all the hard times, too. The glitz of nights out had masked the difficulties of the daytime, working temp jobs and scraping together enough money to eat and pay the rent. Even the evenings had had their shadow of desperation, as she and her friends had searched for suitable men in the pubs and night clubs. They'd never admit out loud that that was what they'd been doing, even now, but she could at least be honest with herself.

Her life was so much better now. Shaun was devoted to her, and she to him. They owned their house, thanks to that bloody lucky lottery ticket that one of Mum's friends had given them as a wedding present, had steady jobs, and Peter was the light of her life. And there was another on the way, a girl, the doctor had said. Donna wanted to name her Alexandra Eileen, but Shaun was having none of it, saying it was too posh. Anyway, it was everything Mum had always wanted for her, and the tension in their relationship had eased. Not that Mum would ever get off her back, but at least now she wasn't completely disappointed in her daughter. Of course, every life had its trials and difficulties, but for the most part, they were comfortable. Scrunching her shoulders, she grinned happily. I should take time like this to appreciate it all more often.

Following her whims, Donna turned off the street into the park they'd visited earlier that day. It was now deserted, with tall lamps casting yellow patches of light on the concrete path every so often. She wouldn't normally wander into a dark, empty place like this, but there were plenty of people walking the sidewalks that bordered it, so she felt safe enough, and it seemed like a nice place to stroll through. Scanning the path ahead, just to be sure, she continued walking when she determined there wasn't a soul along it.

As she reached about halfway across the park, she realised she'd been wrong: a lone figure hunched forward on a park bench, holding his head in his hands, about twenty feet away from her, dimly illuminated by a nearby lamp. She halted and was deciding whether to continue past him or turn around when he spoke.

"Hello, Donna."

She squinted into the darkness to get a good look, but the voice, a slightly raspy light tenor, was vaguely familiar. It took her a moment to realise why. "You're that bloke from earlier, from right here, aren't you?"

"Yes." He sat up, and she could see his face better. "David."

Her heart skipped a beat as the strangeness of the circumstance hit her, meeting the same person twice in the same place on the same day, and she took a step back. "You live on that bench or what?"

He laughed softly. "No. I just had a good time here today. I thought I would come back and enjoy the evening, too."

"Just so you know, sitting here in the dark, in a deserted park by yourself, that's bloody weird, mate."

"Oh, I'm well aware." He flashed her an impish grin. "What about you? Wandering through said deserted park, alone and with child."

Donna rolled her eyes with a brief shrug. "Yeah, you got me there."

"Sit a spell?" He patted the bench beside him.

She glanced at the spot he touched, then back at him. Somehow, he seemed trustworthy, and without a second thought, she joined him.

"It's a lovely night," he remarked, staring up at the half moon above the trees.

"Yeah. Wish we could see the stars here." She waved a dismissive hand. "Too much light pollution."

"Me too. The stars are beautiful. I'd love to see them again."

Donna frowned at the wistfulness in his voice. Odd bloke, she thought. "So." She cast about for something to say. "What do you do?"

He shrugged. "Nothing really. I used to be an actor."

"Blimey, that's exciting! Telly? Or films?"

He shook his head. "Nothing you've seen. Gave that up. Started travelling."

"Well, that's exciting, too," she replied with a few encouraging nods. "Me, I stay here. Job, family, you know. Barely been out of Chiswick, except on holiday." He turned and gazed at her with the saddest eyes she'd ever seen. She remembered what she'd said earlier in the day, that his eyes seemed to go on forever, and this time his sorrow seemed bottomless. She hastened to assure him. "It's okay, you know. I like Chiswick. My whole life's here, and I'm happy."

"Oh, Donna Noble," he breathed, "I am so glad that you are."

Jerking back, she stared at him with narrowed eyes. "It's Donna Temple-Noble. I haven't been called Donna Noble in over five years. How do you know my name?"

He twitched in surprise. "Oh, er, you mentioned your mother earlier. I just guessed from her name." Shrugging, he rubbed the back of his neck.

"No, you didn't 'just guess'. You knew my name!" she spat at him. "How did you know that? Are you a stalker or something, bench boy?" Unconsciously, she readied her hand to unleash a slap, or a punch, if necessary.

"Okay, okay!" Holding up his hands to calm her down, he drew a quick breath to explain. "Yes, I've seen you before. We've never met, but I do know your name."

She cocked her fists on her hips. "And when was that?"

"Maybe a year or two before you got married."

"Oh." She swallowed as unwanted memories, or lack thereof, popped into her mind. "That's when I was sick. I don't remember much from that time."

That inexplicable sadness returned, weighing down his whole body. "I know. I'm sorry."

"What else do you know about me?"

He ignored her question and dropped his head to stare at his hands. "It was great seeing you again today. I didn't expect you to come over and talk to me."

"Well, like I said, I thought I recognised you. You really look like my mum's friend."

A touch of humor tinged his voice. "Yeah, I'm sure I do." His lips curved into a brief smile, but it quickly vanished, replaced again by sorrow.

Sometimes Donna had these urges to take a leap of faith, to jump in and try to help where she suspected she wasn't wanted. They usually backfired on her, so she had learned to resist them, most of the time, but this time, she couldn't help herself. This man seemed so lost, and it tugged at her heart. Placing a hand on his shoulder, she leaned forward and murmured, "What's wrong, David? Why are you so sad?"

He looked up at her with those wide eyes that almost swallowed her with their darkness and gave her a joyless smile. "I'm going away tomorrow. Never coming back. Don't want to go, but I don't have a choice."

Murmuring a soft "Awww," Donna frowned in commiseration and consoled him by stroking his arm. "Never say 'never'. Going away where?"

"Everywhere. Anywhere you can think of." He glanced up at the sky. "Out there."

This conversation had definitely gone around the bend, but for some inexplicable reason, Donna felt comfortable in it. "Up into the sky? What are you, a spaceman?"

David burst into laughter, a healthy laugh full of wonder and humour. He stifled it with a hand and, drawing it down his jaw, murmured, "Oh, perfect! That's just perfect!"

Donna held herself back from the slap that she was starting to feel he deserved. "What's perfect?" she sneered.

He gazed at her, his eyes gleaming with fondness, and hid his smile behind his hand. "Nothing. I'm just a traveller, Donna, but you can call me 'Spaceman' if you like."

"I might just. You are far out there." She shook her head in disbelief.

He snorted and gazed back up at the sky. "You have no idea."

Running her tongue over her teeth, she decided to voice her confusion. "Then why do I feel like I know you?"

"I don't know. Do you?" He turned and their eyes met.

She was wrong: it wasn't darkness that she saw in his eyes. It was the universe: the infinite blackness of deep space, with billions of stars, pinpoints of light, shining, glimmering, calling to her. She was falling - no, flying - into him, and their lips met, their kisses soft and tentative at first, then hotter and faster as they devoured each other, their eyes locked. One of his hands grasped hers while the fingers of the other tangled themselves in her hair, clutching her to him. She was captured, embraced by those eyes that shimmered to golden life with reflected lamplight, and she had never felt so loved, so protected, so treasured, except when...

"Oh my god!" She jumped back away from him and he let her go, though he held onto her hand. "You're the Doctor! Oh. My. God."

"No, Donna." He shook his head. "I'm not the Doctor. I'm David."

She was almost bouncing up and down on the bench, her lips an astonished oval. "Yes, you are. You're the Doctor! I remember everything! You've come back for me!"

"No, I'm not. You can tell. In here." He raised his free hand to tap her lightly just behind her ear.

So many thoughts, images, memories were whirling through her mind, though they weren't as chaotic, as hot and painful as she remembered them, and she had to concentrate to understand what he meant. She looked at him again, and he was right, he wasn't the Doctor. Somehow, she could tell that this man was neither the Doctor nor the other Doctor, the one born from her touch, though he was physically identical to both. "You're right. I know you're not him. Who are you, then?"

His tongue flicking over his lips, he paused, obviously trying to find the right explanation. "I.. I'm... Heh, this is difficult. You know the Doctor has a device that can make him human, right? He used it once when he was travelling with Martha."

"Well, duh, I have his mind. Of course I know that."

He sandwiched her hand between his. "Well, he did it again, and that's me."

"You are kidding me! You're the Doctor as a human?" When he nodded, her jaw dropped. Then she glanced down at their hands. "Well, obviously. You're warm. The Doctor is a walking popsicle." Leaning back a bit, she glanced over his whole body, assessing him as a human. "Why would he do that again? It was a bloody disaster last time."

"Honestly, I don't know. It's not exactly a party this time, either."

An insight flashed through Donna's mind, and she gasped. "You're opening the watch tomorrow, aren't you?"

He nodded.

She covered her mouth with her free hand, her eyes wide with horror. "Oh, I'm sorry, David. I'm so sorry."

He patted her hand in his. "Don't be. I'm ready for it, as much as I can be. I've had a good life."

"You're braver than I'd be. I'd be running around screaming."

His lips curved into a humourless smile. "Believe me, it's taken a lot for me to get this far."

"Why are you here? You should be with your friends."

He shook his head. "I'm with my friend. This is exactly where I want to be right now."

Her eyes widened as the realisation hit her. "You called me out here."

"Yes. The Doctor..." He wagged an index finger. "Not our Doctor, but the next Doctor... he's helped me cope with all of this. He's given me some telepathic ability, so that I can hear him. It's helped me more than I can describe. But I also used it to try to guide you out here. I..." He ducked his head to hide his face. "I feel so dirty. The Doctor would never use this to force anyone to do anything, but I had to get you here..." He gulped. "It was not easy. I've been trying since sunset."

She smirked. "You know, I'm missing my programmes for this."

"I'm honoured by your sacrifice." Grinning, he squeezed her hand. "I wanted to see you happy one more time. And the Doctor inside me, he wanted to see you again. He misses you."

"I miss him, too. More than I can say. Always have. I didn't know that I did, but I do now." She touched her lips. "Was that kiss him? Because..." She paused, hesitant to believe that the passion she had felt in the kiss had come from her best mate. "I didn't know the Doctor loved me like that."

"He doesn't." David backpedaled as soon as he realised what that sounded like. "No, I didn't mean it that way! It's just... The Doctor doesn't love anyone like that, not like you're thinking. You might think it looks like that, but what he feels is so much more, more than just human romance and desire." Bouncing once on the bench, he glanced around at the park. "Ah, I can't describe it! English just doesn't have the words!" He threw his hand up in frustration.

Donna mumbled a couple of words, and David frowned. "What was that?"

"That's the concept, in Gallifreyan. Can't say it in English, unless you want me to write you an essay. Don't got any paper on me."

David smiled, impressed. "I suppose. I don't know Gallifreyan." He sighed. "Oh, Donna. He's a Time Lord. That kiss couldn't have come from him. That kiss was from me."

"You?"

"Yes." He sighed again, sounding so sad and lost. "I'm not going to explain everything, because it would take too long and accomplish little, but just understand that I know you very well and I care about you. And, the longer I carry the watch with me, with my mind open, listening to both my Doctor and the new Doctor, the more I become him. I can't help it anymore."

"That's why you understand him so well."

"Yes. I think like he thinks, and feel like he feels. It's all a mess inside me, jumbled up with who I am, if I'm anyone. And..." He faltered. "And what he feels for you, well, it fills my heart. There are others he cares for, but none so much as you."

He breathed deep into his chest, its stutter shaking him visibly. "Donna, I'm only human, and I can only interpret him as a human. I love you, Donna. I truly, truly do. You're the most important woman in the universe to me. And that's why I'm here, to convince myself that you're happy and you're living the life you want, because I really need it to be true. And I brought the Doctor back to you, for just a little while, because he's all I have that I can give to you."

Stunned by his declaration, Donna was at a loss for words, for once. "Thank you," she murmured, knowing it was entirely inadequate. She felt she had to elaborate, for him. "I am happy, you know. I love Shaun and Peter, and this little one here." She patted her stomach. "Maybe I'm not exploring the universe and hobnobbing with aliens, but I've got family and purpose and love. I miss the Doctor and I wish I could still be travelling by his side, but this life is good, too. And, well, normally, I don't miss him, do I?" She tapped her temple with a smile, then cocked her head in sudden confusion. "Wait. Why am I not dying? I should be burning up."

David straightened, his jaw set with determination. "Because I won't let you."

"What?"

He held up her hand, sandwiched between his. "I've maintained contact. I'm not letting the Doctor's mind overwhelm you. I'm siphoning off enough that you can work with what's in your head without it harming you."

Alarmed, she tightened her hand on his. "That's got to hurt!"

"Quite a bit, but it's okay." He smiled, but she could see that he was waging a silent battle against the searing pain in his head. The golden glow in his eyes, slowly but steadily growing brighter, was evidence of that war, and not just glints of lamplight as she first thought.

"You have to stop that!" she screamed. "It'll kill you!"

"No." His refusal was firm. "Not until you're safe again. I won't let you hurt, Donna, and I won't let you die."

A tear rolled down Donna's cheek, and she caught his gaze, looking deep into his eyes. "David, I..."

He pressed a finger to her lips to silence her. "You don't have to lie, Donna. I know you don't love me."

"But I..." He squeezed her hand and she fell silent.

"It's okay. I may look like your mate the Doctor, but I'm not him. You barely know me." His gentle smile lit up his entire face, glowing with his love for her. "I'm content to see you happy and safe. And honestly, it won't matter at all come tomorrow."

Her frustrated sympathy burst from her. "How are you so bloody calm?"

He shook his head. "Maybe it's the Doctor helping me. Or maybe I've just gone mad. My friends think it's the latter, I'm sure."

She stared at him in wonder. "You're just like him, you know. Bloody Martian martyr syndrome." Swallowing against a sob, she sucked in a stuttering breath and calmed herself. "Please make me go back, David. I don't want you to hurt anymore."

David nodded. He cupped her cheeks with both hands, just like he did a year before under hot studio lights with a dear friend who had the same flowing ginger hair, and collected her tears with his thumbs. "You'll see the Doctor one more time, I promise. He'll be there for you when you need him." He planted a light kiss on her forehead, then closed his eyes, wisps of golden energy floating away from them and dispersing in the darkness. After a moment, Donna's eyes turned glassy, then drooped shut as her body went limp. David continued to concentrate for a few more seconds, then opened his eyes, now dark and cold. "I've taken your memory of me as well, so that you'll think I'm him when you see me." He laid her down on the bench and kissed her again on her cheek. "I'll see you once more, Donna, when I kill you. I'm so sorry."

As he moved to conceal himself behind a tree, David massaged his temples, breathing a sigh of relief at the cessation of the blazing pain in his head. He'd barely been able to see her through the hazy golden curtain that the agony had drawn over his vision. Exhausted, he leaned against the tree and watched over her as she slept. Presently, Donna propped herself up and groggily started to berate herself. "I went and kipped in the middle of a bloody park! Blimey! What's the matter with me?" Pushing herself to her feet, she brushed her clothes down with her hands and stalked off towards home. David watched until she disappeared from view, then, murmuring under his breath, thrust his hands in his trouser pockets and began his last hike back to the TARDIS.