John had never considered himself suicidal, by any means.
Sure he was a risk-taker, sure the adrenaline rushes were fun, but this? Whose stupid idea even was this? Why did he ever agree to this, when it was so soon, so soon after Sherlock came back, and now THIS? Whose. Idea. Was. This.
Then he remembered; he had brought it up, during a row with Sherlock. He had been trying to get the other man to see just HOW much he had been hurt, how much he had needed Sherlock to be there, he could even have gone with him, hell, he'd have welcomed it! But then he had asked 'How would you have felt in my shoes?'
Which led to him standing on the rooftop on St. Bart's with his phone in his hand, waiting for Sherlock to step out of the cab. He had to think of what to say, trying to remember; what had happened? Tears leapt to his eyes as he thought about that day; as they called it now, "The Incident". Sherlock had been on the rooftop; he remembered the raw emotion in his voice. He could even imagine the man had been crying…he had been scared. John knew that now, had seen it in his return, in his eyes for days afterwards. Scared he'd lose John, Mrs. Hudson and Lestrade. Scared he'd lose the only people that meant anything to him, because he meant something to them. John imagined it; a sniper on Lestrade (oh my god). A sniper on Mrs. Hudson, blissfully unaware, sipping tea (oh god that's not right feeling a bit queasy). A sniper on Sherlock (NO).
John nearly felt his knees buckle at the last, a stab of panic so intense it hurt and wrought tears to his eyes as he imagined it. And then he understood. He understood why Sherlock had done it, understood more thoroughly than all the times he'd made the detective explain. Oh god, oh god, oh god, it seemed to be his pulse speaking the words as it ran frenzied through his veins. He shook his head slightly and started as he saw Sherlock get out of the cab, He was here. Steady, soldier. Oh god why had he ever said that.
Sherlock blinked up at John; a figure on the roof, silhouetted by the grey clouds of London (nostalgia hits three years it was him and there was John where he was John is he alright John he knows the feeling and there was nothing he could do oh that hurts alright Sherlock stop). He knew what to do; went to walk forward, picking up his phone when it rang.
"John?"
"Sherlock—I…"
"John, are you alright?"
"I—I'm fine. But—"
"No, don't speak, I'll get you down."
Sherlock turned to move and John remembered a flash.
"Stay exactly where you are."
"Stay exactly where you are!"
"Would you do this for me?"
"Would you do this for me?"
"Please…"
"Please…"
The words, familiar, rang back to Sherlock, seeming to bounce from his lips to John's and back into his ears, settling, nesting, creating a rather unpleasant feeling to start boiling up. One he hadn't cared about until he'd met John, one that had nearly brought him to his knees in the severity of it, one that had made him fake his own death, jump off a roof, in the severity of it.
Fear.
The chill running through his veins (fear he's afraid oh john he must have been afraid and confused he knew he hurt him he KNEW it had hurt but this much never this much oh god)
"Goodbye, Sherlock."
John couldn't believe that he was about to do this; but he cast thought aside, cast everything aside as he dropped his phone behind him, took a last lingering look at Sherlock…
and fell.