It was 3 am, John was exhausted. He and Sherlock had just chased a murder suspect to Greenwich Market (he made a poor attempt of hiding under one of the stools). Thanks to Sherlock's knowledge of Indian cutlery they had found him within minutes and had brought him out onto the street where Lestrade was waiting to arrest the man.
They were now walking through Greenwich Park, it was a cold October night, there was a clear sky that night and you could see a number of stars shining through the trees, fighting against London's pollution that usually prevented them from showing off. Sherlock deep in thought, no doubt cataloging the case in his hard drive, and John was too tired to talk so they walked together side by side in silence.
As they reached a secluded part of the path, Sherlock stopped. There was a gap in the trees and he looked through it at the silver dots spread out throughout the sky. He half smiled. The sky was so beautiful at night.
To John's surprise, Sherlock sat down on the grass and slowly lowered his body until he was lying flat on the ground, staring into space.
"Sherlock, what are you doing?"
"Let's waste time... chasing cars..." he felt the grass around his head, gently pinching it between his first and second finger, "around our heads." He seemed to find what he said amusing as he smiled dreamily.
"What?" asked John, completely confused and taken aback by this soft, dreamy Sherlock laying at his feet.
Sherlock patted the ground beside him as an offer for John to lie down too.
"I need your grace to remind me..." he looked back up at the sky as John laid down beside him, "...to find my own." Quietly Sherlock asked, "If I lie here, if I just lay here, would you lie with me and just forget the world?" It was a very odd thing to say. John assumed Sherlock must be as tired as he was and so didn't know what he was saying. Sherlock looked at him, he didn't look crazy, John thought.
"Yes," he answered. Sherlock rolled onto his side so that he was facing John, sitting up slightly so that he was leaning on his elbow.
"Forget what we're told? Before we get too old?" His eyes seemed both distant and fully aware at the same time. John got the impression that this, whatever this was, meant a lot to Sherlock.
"Yes." A few leaves fell from the trees surrounding them. Sherlock watched one flutter in the air until it settled on the ground.
"Show me a garden that's bursting into life," he whispered.
"I didn't think you liked nature," John teased. Sherlock laid down on his back again and continued star-gazing.
"All that I am... all that I ever was," he looked at John and slowly stroked his cheek with the back of his finger, "is here in your perfect eyes, they're all I can see." John blushed as Sherlock took his hand away.
"If I lie here," John began, "if I just lay here," Sherlock smiled as he took John's hand in his, "would you lie with me and just forget the world?"