It was years later, almost a decade, in fact, since John and Sherlock moved in and solved their first case together. A few years after 'the fall' and their reunion, a couple after Mary's unfortunate death, and even a few years after Mycroft's diagnosis. And over those years, the memories of Chloe disappeared once more into the confines of the mind palace. That is, until a particularly tricky case forced him to face his demons. Literally.
It started with a disappearance, and turned into a murder. A wife went to The Yard to report her missing husband, and when the man turned up dead in a hotel room a few days later, Sherlock was put on the case. It was obvious that he'd slipped away to visit a mistress, but not so obvious that the mistress was the killer. When the clues all clicked together in the genius's head, the solved case caused him to lay stoic on the couch, silent and unmoving for several days. He was thinking. Considering whether or not he was going to apprehend the murderer himself, or send Lestrade a name and leave it at that.
Finally, he settled on a happy medium, and Lestrade, John, and Sherlock found themselves standing on the porch of a large mansion house just outside of London. The DI rang the doorbell, and an American woman with long blond hair and emerald eyes opened the door. "Police, ma'am. May we come in?"
The eyes flitted from John, to Lestrade, but when they fell on Sherlock, there was a mischievous glint to them. "Of course." She led them to a sitting room and gestured for them to sit on the couch. Sherlock remained standing, and not even a single feature in the marble face moved, especially when Chloe sat herself down on the couch, practically on top of John, and crossed her legs, very visible under the extremely short skirt. "What brings you officers by?" She flashed her melting smile in John's direction. "Especially such a strong, dashing one as you." She extended a red clawed hand, and John took it, a blush covering his whole face. "Chloe Melbourne."
"Uh, John Watson." Sherlock frowned as he saw the cogs stop turning in John's head.
He cleared his throat and the small party turned to look at him across the coffee table (Lestrade had been shamelessly ogling their suspect as well). "Mrs. Melbourne, we're here about the murder of Robert Greyson, I'm sure you're familiar with the name." His glare was hard and hot. "Seeing as you killed him after you two met up on January 6th."
John's jaw dropped. "Wait, I thought the husband was the murderer?"
"I never said that." Sherlock said, his eyes never leaving Chloe as she got up and went over.
Standing as close as she could get to him, she placed her hands flat on his chest and purred. "I had to kill him, love, you see he was-"
"An easy fuck?" Sherlock cut her off.
Fear flashed momentarily in the green eyes, before she tried a new tactic. "Oh, my little Lock-and-Key," She snaked her arms up to wrap around his neck and pet the base of his curls just the way he liked it, "I have missed you, you kn-"
He grabbed her wrists so fast it shut her up and caused John to jump to his feet and pull his gun. Chloe squirmed under his gaze and grip. "Babe, you're hurting me."
"Never call me that again." He practically growled, throwing her hands down to her sides so hard, she dropped the floor. John and Lestrade were standing in the vacuum of an awkward moment, and could only watch the confusing events unfold before them. "Get her out of my sight." He said to Lestrade, his eyes still burning with anger.
"You always were a coward, Sherlock Holmes!" Chloe yelled after him. "There wasn't much of man to you then, and even less now. You didn't even put up a single fight that last day of school."
The last sentence was like a wall that Sherlock walked into. It stopped him, spun him around, and pushed him back into the living room. "You stole everything from me. My ability to trust others, my patience for normal people, but especially my innocence. Rot in hell, Chloe Jones!"
He stormed out of the house in a flurry of black trench coat, leaving behind a smirking killer to get clapped in hand cuffs. John had to run to catch up with his friend. He'd never, ever seen Sherlock lose his cool like that before. The doctor decided this was a story he would never ask about, and would probably never hear, especially since Sherlock snapped at him, too, when John tried to take his cigarette away.
They walked in silence all the way back to 221B, Sherlock having made his way through three smokes before they reached their front stoop. Still, the detective didn't speak, only made his way to his room, and remained there for the rest of the evening, and all through the next day.
John never did hear the story from Sherlock, but apparently their murder suspect told the whole story, almost as if she were bragging about it, to a disgusted Lestrade.
Three months later, a news story came out about a blond-haired American woman who had been killed in prison. Sherlock and John had been passing a news stand, when the black and white photo jumped out at them. Sherlock only paused to read the caption under the picture, then continued to his destination, though John swears he saw a little smirk.