"Where are we?" Rose asked. When the Doctor only smirked, she amended her question. "When are we?"
"About six billion years into your future." He came around the console of the Tardis to stand beside her and motioned towards the door. "Well, go on, what are you waiting for?"
He watched as she ran forward, caught up in the excitement of somewhere new. She glanced back over her shoulder at him, grinning, and threw open the door. "Wow," she murmured, gazing out at the lush green grass that seemed to go on forever. She started to step out, but her foot went through the grass and plunged into water. "Yuck!" Rose jumped back, and the Doctor laughed.
"It's all water," he told her, opening the other door and gazing out at the never ending sea, obscured by water plants. "No land. We're simply floating."
"No land? No people?"
"Don't speak too soon, Rose," he said, motioning out over the water where a small thatch raft floated. They watched for a few moments before a creature surfaced and pulled itself onto the raft with its spindly arms. It was sleek and all grey, reminding Rose of a catfish. The creature's eyes were wide-set and it had fins running up its legs and arms. After a long moment it turned and studied them for a long moment before raising its hand in a wave. The doctor grinned and waved back. Then as swiftly as it had come, it took a rope in its hand and dove into the water, swimming away and pulling the raft along with it.
The two watched the raft disappear over the horizon before Rose asked, "How did you meet him? Or her?"
"Never met it before in my life," He replied, turning away and going back to the console. "And I think their pretty genderless."
He babbled on about some man-eating fish that lurked in the depths on this world, but Rose wasn't really listening. She got on her knees and leaned out of the Tardis and towards the sea grass a foot or so below. Beautiful flowers bloomed on the ends of each stalk, their long petals twisting into spirals, starting out purple and slowly turning to a deep gold at the tips. It was farther down than she though, so she lay on her stomach and reached out, plucking a perfect flower. She laid it on the floor of the Tardis and reached for a few more, thinking she could put them in a vase in her room. The water beneath her rippled, but she was focused on the flowers and didn't notice.
The doctor finally realized she wasn't listening when he heard her distant hum. "Rose, what are you…" he trailed off, his question lost as he watched rose laying on the floor, reaching out of the Tardis collecting flowers. He leaned against the railing and smiled, perfectly happy watching the sun glint off her golden hair, hearing her hum happily and seeing her smile as she pulled herself up, hands full of the delicate flowers.
But then he heard her scream.
"Next time I tell you about the man-eating wildlife, do listen," he chastised quietly as he bandaged her hand. She was sitting on the table in the medical room, soaked to the bone, her wet hair and clothes plastered to her. "Good thing it wasn't a big fish, it would have done more than scratch your hand and pull you into the water."
"And good thing I can swim," she said with a small smile, but the Doctor didn't let up, and she knew why. Her getting hurt so easily scared him. Anything could have happened, she could have drowned, she could have gotten killed, and it would have been on his hands. "I'm okay," she finally whispered.
He paused and looked up at her, his deep eyes full of worry, and he wrapped his arms around her, pulling her into a big, soggy hug. "I know, it's just that I heard you scream, and…" he trailed off and she pulled back, still in his arms, and looked up at him. Her eyes said it all. That she trusted him. That she needed him. His hearts stilled. "Rose…" he started, lost in her eyes, unable to get his thoughts on order or really think at all. She slid off the table and stood on her toes, and cutting him off with a kiss. He melted against her soft lips, pulling her tight against him. His tongue flicked her bottom lip, teasing it open, and then they were kissing, really kissing, and he thought both of his hearts were going to explode.
Then a terrible thought crossed the Doctor's mind. Love. That's what this was, the world spinning, every touch, every smile, something more. Nothing but him and rose in his arms. His Rose. Finally. This was love. He couldn't do this. He couldn't do this to her. She needed someone who would settle down with her, someone to take care of her when she got old. She didn't need him. Never growing, never changing, coming home with a new face, stumbling across the universe in a little blue box.
And he pulled back.
Rose let out a long breath, her lips pressed together like she was holding in the kiss. Finally her eyes flicked open and she smiled up at him. Her smile dissipated as she studied his face, he was frowning.
"Damn it," he murmured, and she pulled back, the hurt evident in her eyes.
"Really? We kiss and the first words out of your mouth are damn it?" she shook her head in disbelief and pulled away as he caught her arm. She turned away, furiously wiping away the tears that gathered in her eyes, and disappeared in the back rooms of the Tardis. The Doctor watched her go, heart heavy. He didn't follow her. He didn't try to explain himself; he didn't admit that he loved her more than she would ever know. He couldn't admit that. Not even to himself.