Sherlock and John were out for lunch one day, a rare time between cases where Sherlock actually felt like eating. He was testing John's deduction skills. He'd just failed miserably on a man sitting across the street waiting for a bus. John thought the girl sitting next to him was his girlfriend, whereas Sherlock rolled his eyes and told John the man was obviously gay.
"That couple... there," Sherlock said, pointing out two people holding hands, walking down the street. "Do them."
"Newlyweds," John said immediately, recognizing the dusky rose shade that linked them.
"Yes." Sherlock actually sounded surprised. "How did you know?" Sherlock glanced at him suspiciously.
Oh crap. John swallowed his mouthful of coffee. "Look at them," he said, like it was entirely obvious.
Sherlock looked again. "Of course, look at the way they're holding hands, not to mention..."
Sherlock continued for a while longer, but John wasn't listening. Close call, he told himself. You're going to have to be more careful or he will notice something. That's what he does.
"I don't have friends."
But that was entirely untrue, because John could see the purple link connecting them, knew that there was an almost purple bluish link from Lestrade. But Sherlock was in A Mood, and besides, John could never tell him that. Could never tell him that he was One of Them, that he could see them, because Sherlock would insist on experiments and using John for many things. He wouldn't be able to take that.
Some things were meant to be kept private.
So John just replied sarcastically and went off to bed.
Sherlock corrected his statement in the morning. John smiled on the inside and the knot pulled tighter, as if afraid one of them might let go.
Ties didn't disappear in the blink of an eye, as soon as a heart stopped beating. They faded slowly, never on a specific schedule, but they snapped free and faded.
They let go and gave up.
When Sherlock fell through the air, the line streaming down through the sky like one part of a rainbow, John knew what would happen. He was a doctor. How could he not?
He'd never lost a purple strand before. He didn't know what to expect.
It hurt, just like he knew it would. It was hard to tell whether it was his link or his heart that was screaming.
The magenta violet strand never left John. He'd heard stories about people that couldn't let go, that lost the other end of their tie but couldn't believe it, that held on so strongly the tie still existed with no other end, just flapped about in the breeze somewhere far away, but he couldn't believe that.
He wasn't one of those people. He still had hope that one day, he would see the knot coming back into view and the other end of his tie would appear.
He had to hope. It was all he had.