One night. That was it. One night four years ago. Four years, three months and twelve days, if he was being specific and he could still feel the wind on his face as he threw himself off the roof of St. Barts. But it wasn't the memory of wind that kept him sane while he was away protecting the ones he loved the most.

It was her.

He'd gone to her, broken and afraid, a fraud, and she, with her unfailing faith did not doubt or interrogate. She'd only wanted to know one thing.

"What do you need?"

And in that moment he was honest with himself, more honest than he'd been in years. It wasn't the smell of chemicals that made his heart rate increase when he entered the lab, an excuse he told himself more than he cared to admit. Nor was it the excitement of catching criminals, another defense he employed often. It was the big brown eyes that would glance at him over the lenses of a microscope, the furrowed brow of a woman who struggled with her surgical gloves, the bottom lip captured between white teeth as it was chewed in concentration. He only needed one thing. He only ever needed one thing.

"You."

It was those thoughts that propelled a dead man to the doorstep of Molly Hooper. She was surprised, as he'd anticipated, considering that after their plan was a success the two parted ways, an unspoken goodbye hanging in the air between them. But that wasn't enough for him and if, when she opened the door, her red-rimmed eyes were any indication, it wasn't enough for her either.

For four years, three months, and twelve days it was the memory of their night that sustained him through cold nights in cramped spaces as he waited without any leads on Moriarty's criminal empire. The feeling of her mouth against his as she pulled him through the entryway, her nails raking through his dark curls, gently scratching against his scalp, made those dreary nights bearable.

When he'd woken up the next morning the sun was nowhere to be seen and streaks of moonlight peaked through the drawn curtains of Molly's bedroom, illuminating her sleeping form. She was curled next to him, soft puffs of breath beating against his bare chest, her eyelashes fluttering against her cheek as she dreamed. He stared for a while, memorizing every inch of her (as though he hadn't already) and stored her image in his mind palace, although even if he hadn't he knew he would never be able to forget the way they…

When he stayed as long as he knew he possibly could, he slowly slid out of bed, careful not to stir her. He picked up his clothes that had been haphazardly thrown about, chuckling softly at the way she'd laughed at him when he, for the life of him, could not get her "blasted contraption" off. He stopped when he saw her stirring. Her eyes fluttered open, still glossy with sleep, but as she looked at him, she knew. He leaned over the bed and pressed a chaste kiss to her lips.

"I will be back, Molly," he whispered in the darkness.

"I know you will be." Her unyielding faith, once again, caused the corners of his mouth to turn up in a smile that didn't quite reach his eyes.

"Goodbye, Sherlock Holmes."

"Goodbye, Molly Hooper."

By the time he reached the door to her bedroom, she had already fallen back to sleep.

As a dead man he exited her flat and walked out into the street, unrecognizable. A part of him, the small part in the deepest, darkest corner of his heart, the part that held the sentiment he so desperately tried to conceal, wished he could stay, wished the two of them could have woken up together, been domestic as they shared shy smiles over coffee and simply enjoyed each other's company. He wanted that more than he'd ever care to admit but instead of waking up next to the woman he loves, he was walking away from her, the moon still high in the sky.

But now…now he is back.