Many thanks to tumblr user sherlolly-is-jolly for the prompt. Inspired by "Hallelujah" by Paramore.
Sherlock cocked his head to the side curiously. It was nearly midnight, and the halls of St. Bart's were nearly completely empty. However, tonight Sherlock could hear the undeniable sound of drums and electric guitar emanating from within the usually quiet morgue.
Carefully opening the door, he found the source of the music. Molly Hooper had her back to him as she sterilized her equipment and cleared her lab bench. On a nearby counter, her iPod was playing a song he did not know.
"This time we're not giving up. Let's make it last forever," Molly sang along.
Sherlock was absolutely transfixed. He watched carefully as the pathologist's head bobbed and hips swayed in time with the music. He had never seen her this way before, so uninhibited. He smiled to himself; he rather liked this side of Molly.
At that moment, the specialist registrar turned around to see the shadowy figure in the doorway and let out sharp gasp, raising the metal bowl she was holding in on hand. He quickly stepped forward before she started throwing things his way.
"Sherlock!" she sputtered, clutching at her chest. "I didn't think anybody would be here at this time of night. What are you doing here?"
"I was running some tests back at Baker Street and realized that I was in need of a few spleens, but I think it can wait until later," he answered quickly. With that, he turned on his heel and strolled out of the morgue, leaving a confused Molly in his wake.
It had been a week since Sherlock had seen Molly in the morgue that night. It had taken that long for him to get everything ready. Now, he strolled into the lab and greeted Molly. "Good evening, Molly."
"Hello, Sherlock," she responded brightly. "Are you here for those spleens? My shift's just ended, but I can grab them for you."
"No, that can wait until later. I'm here because I need you to come with me."
"Well, you're in luck because I'm just about finished here."
"Excellent!" he exclaimed and gently ushered her out.
"Sherlock, what exactly are we doing here?" Molly inquired as the two of them walked beside each other through Hyde Park.
Instead of answering her, he placed his hand on her lower back and guided her off the path and onto the grass. Waiting for them was a large blanket carefully lain out on the ground. On blanket were two plates of pasta, two glasses, and a bottle of her favorite wine.
"What's all this?" she asked, eyeing the setting before them.
"Dinner," he replied simply. He took off his suit jacket, rolled up his sleeves, and settled onto the blanket. "You're welcome to join me any time you're ready," he said to her when she didn't follow him.
Molly mentally shook herself and quickly sat down as well. She noticed that the bandstand had been set up with instruments and sound equipment. "So what kind of case is this? Are we reenacting a murder? Did someone die during a concert?"
"Who said anything about a case?" the detective asked, confused.
"You did, back at Bart's."
"I merely stated that I needed you to accompany me. There was no mention of a case."
"If this isn't for a case, what is all this for?"
"It's a date," he replied as if it were the most obvious thing in the world. Molly stared at him blankly. "You know, where two people who like each other go out and have fun."
Molly was shaken out of her shocked state when the first chords of electric guitar sounded. Looking up, she found yet another surprise. As they were talking, a band had gotten onto the stage. Not just any band; it was Paramore, one of her favorites. They were her guilty pleasure; she had always felt that she was a bit too old to be listening to their music.
"How did you know?" she asked, turning to Sherlock.
"That night in the morgue. You were singing and dancing to this song. I went home, did a little research, then invited them to come here for a private performance."
"How did you manage that? They're on tour in the States."
"Nothing a few phone calls couldn't fix," he answered with a grin.
"So you did all of this for me?" She gestured around them. "Why?"
"The song you were singing. After I looked it up and listened to it, I found that it rather fit what I have been wanting to express to you." At her confused expression, he continued. "I know that, in the past, I have been rather awful to you. I have done so in an attempt to keep my distance because I have always believed caring to be a disadvantage. It has recently come to my attention that, in fact, I have been a fool for assuming such things. Thus, I have finally decided that I must act on my…feelings. We have been through a lot together. I have nearly lost you many times before. I will not lose you again. I wish to pursue a romantic relationship with you, and I have every intention of making it last forever." He swallowed thickly and looked into her eyes.
Molly smiled at him as the final notes of the song rang out. Instead of answering him, she lean forward and gently pressed her lips against his. She pulled back and looked at him happily. "Yes," she breathed. "I accept your offer."
At this, he wrapped his arms around her and pulled her tight to him. The two of them spent the rest of the night enjoying each other and their own, private concert under the stars.