He had to double check everything, which was unusual for him. Discerning the culprit from a misplaced water glass or the color of a shoelace was simple, none of it held any significance compared to this event. Two keys, two locks, two lives to share. It was symbolic and sentimental, something he would have scoffed at just over a year ago. Now, hand in hand with the person that had made him reconsider all that, it seemed like the most logical thing in the world. Traffic hummed in the background as they walked, content to be silent amongst the white noise. The Thames came into view, the midday sun making it shine along with the reflections on modern buildings across the water. The tourists were gawking at The Eye and the Parliament building, but Sherlock was interested in something more commonplace. John's steps got lighter as they approached the rail, he swung their joined hands a bit more freely. The air was a bit chill for the season, but Sherlock didn't feel its bite with the warmth the came from being close to his... him. His "special someone" as the landlady had put it. He wasn't sure on the terminology for all these new feelings and boundaries and expectations, but he and John were definitely "together". And that's what this was about. "Always thought of doing this when I was a kid," John said, leaning against the guard rail. "I'm almost giddy now that it's actually happening." Sherlock thought "terrifying" was a more accurate word. He still wasn't sure he could do this. He was sure about what he felt for John, that was a constant, the problem was in the everyday, being able to give what John needed, to make up for all the shortcomings that were all too apparent in one Sherlock Holmes. There was a lingering thought, a traitorous whisper that this was a trick, that he had somehow manipulated John into whatever this was. It was as if John were under his spell, and Sherlock's greatest fear was that someday the spell would wear off, that John would see him for what he truly was and leave. Despite this internal storm, he nodded that yes, he was excited, yes, he had his lock and key, yes, he had the pen. John took the pen and wrote in his neat-for-a-doctor handwriting, "SH+JW". He handed it back when he was done so Sherlock could do the same. Sherlock concentrated on keeping his hand steady as he inscribed the matching "JW+SH" on to the surface of his lock. It was a task that shouldn't have taken as much space in his brain as it did. "Sherlock, the key...!" He heard John too late. There was a sickening sound of clattering metal and Sherlock's key disappeared into the dark water. For a few moments Sherlock was frozen. The pen hovered in the air, poised just above the drying ink of the "H". "I'm so sorry, John," he said. "I can't-" He couldn't do this. Even this small symbol of devotion. He couldn't open the lock and he couldn't open his heart. If John had any sense, he would leave him, let him be closed off from everything and everyone. John would find someone else. His insides wilted at the loss. He would miss John when he was running through the city streets, he would miss their talks and touches off case, and he would miss holding his hand and feeling his warmth on days like this. The thought of never again hearing his breathy laugh broke Sherlock's heart. But he would let John go if he asked. Because John deserved to be happy, more than anyone he'd ever known. He deserved someone who could make him happy, even if that someone wasn't Sherlock. John took his hand and he was so calm, the antithesis of Sherlock's demeanor. He enclosed the shaking fingers with his own and eased the pen from his grasp. Sherlock dropped his hands to his sides, the picture of defeat. With a light click, John opened his own lock. Sherlock's sat solitary on the rail. To his surprise, John picked up both locks and asked, "Is this a good spot?" "It won't work, John," Sherlock protested. John smiled patiently. "Don't give up on me so soon." He looped his lock through Sherlock's closed one and attached them both to the rail. Sherlock watched with astonishment at the simple solution he had been blind to. "There, see?" said John. He picked up his key and held it toward Sherlock. "Together?" This time Sherlock didn't hesitate. "Yes. Together." It was impossible to hear over the street noise, but Sherlock imagined the "plop" of the key hitting the water was the most satisfying sound in the world.