Sometimes she could see it in his eyes, a sadness that couldn't be explained by anything they had already experienced together in her timeline. His green eyes would get clouded by some memory, but he would never confide in her. She was left to wonder and hope time wasn't running out for them.

The Doctor dashed around the console of the TARDIS, his brown hair flopping and his tweed jacket unbuttoned. He had promised her an adventure, one to make up for the two years he'd been absent while she waited in Stormcage prison. When she tried to help fly, he sent her to sit in the old leather driver's seat and watch. He always was so touchy about other people flying the TARDIS.

"And away we go!" The Doctor exclaimed as he flipped the lever, sending them flying through time and space. He collapsed onto the seat beside River, grinning from ear to ear. "You'll love this, River Song. It's a completely deserted planet except for the beaches and the jeweled birds. Sapphires, emeralds, rubies, all fluttering through the air."

The TARDIS landed with that screeching noise he so loved and he jumped up, grabbing her hand and towing her to the door. He threw open the doors and led the way out into the dazzlingly bright sunshine and the smell of salt water.

River kicked off her boots and let her feet settle in the wonderfully soft sand. She walked to the tide line and sat down, letting the ocean water wash over her legs. The Doctor settled down next to her, his gangly limbs still for once. They sat in silence, enjoying their rare moment of peace. However, it didn't take long for River to get bored.

"Alright, sweetie," she said, jumping to her feet. "You promised me an adventure. What is there here for us? Are these jeweled birds deadly? Are they keeping something else from developing? Are they hiding some kind of treasure from the rest of the universe?"

He looked up at her, that horribly sad look in his eyes again. The Doctor didn't reply, just watched her as the ocean breeze ruffled her already uncontrollable blonde hair. He tried to absorb the image of her standing beside him; the sun on her skin, the drops of water drying on her feet, and the excitement in her blue eyes.

"Sweetie?" She repeated. "Did you hear me?"

He stood slowly and took her hands in his. "I'm keeping you," The Doctor said quietly. "Time can be rewritten."

River tilted her head, confused. "You said it couldn't be. You said that I wasn't allowed to dare. And I'm pretty sure that whatever you want to rewrite would ruin everything. You may be good, Doctor, but you can't foresee all the complications and paradoxes that could result from whatever stupid idea you have forming."

"River," he said. "I'm not letting you go."

The corners of her red lips quirked up in a smile. "That's not your choice, sweetie. I choose where I go. Now," she said. "Please tell me there is something dangerous on this planet."

He started to lead her away from the water. "Well, I heard that the birds may have secret stores of knowledge hidden deep in their underwater caverns. Fancy a swim?"

River's eyes twinkled in the sunshine. "Always. I'll get the air tanks." She sashayed into the TARDIS, leaving the Doctor on the sand.

He watched her walk away, the sadness returning to his eyes. The time was coming when she would leave him for the Library. That thought terrified him, and sometimes he couldn't block the memory of her disintegrating in a flash of light as she sacrificed herself for that damn computer interface. All he wanted was to keep her with him and keep her safe.

But she was River Song, and safe wasn't something she did.