Since you guys wanted a back story. Basically, baby ice prince Sherlock got bored, escaped the palace guards, walked into the forest and met a wizard who took his heart and put a curse on him that can only be broken by his one true love.
The first time it happens, Sherlock is watching Rosie. Well, he’s supposed to be watching Rosie, but the toenails have started fizzing, which they’re not supposed to do at all, and he looks up from the petri dishes at a flash of motion in the corner of his eye to watch as a stack of books (which he’d really meant to pack away) topples in slow-motion horror onto Rosie’s head.
He throws out a hand and flings himself across the room, and it’s not until she’s safe in his arms that he notices that the books seem to have frozen mid-tumble. As soon as he does, they fall to the ground.
The second time it happens a murderer is stabbing at John’s back with a wickedly sharp knife, and Sherlock is too damn far, and he’s running and shouting but it turns out not to be necessary, because the man screams and the knife hurtles out of his hand to stick four inches into a stone wall.
Sherlock punches him in the face repeatedly and nearly strips John on the spot to check for wounds.
It’s the third time that convinces him that something else is going on, something beyond the usual weirdness of his life. Twice is coincidence and three times is a pattern, and the third time is really quite spectacular. The third time it happens, Sherlock is at the park with Rosie, teaching her deductions she’s still too young to understand, and he’s buying her an ice-cream and when he turns around there’s someone trying to unbuckle her from the pram. A moment later the man hits a tree twenty feet away with a wet crack like a falling coconut and slithers boneless to the ground.
In the echoing silence after, Sherlock almost runs back to the flat, dialling Mycroft as he goes.
Mycroft arrives twenty minutes later, out of breath and looking worried, because Sherlock has never, in their forty years of knowing each other, phoned him willingly.
Rosie is asleep upstairs,and Sherlock is sitting in his chair, staring at his hands.
He looks at Mycroft and curls his fingers on themselves.
“Mycroft,” he says. “Something’s wrong with me.”
And he points at a book and watches it float into the air.
“Is that real? Can you see that happening? I’m not high - I haven’t knowingly taken anything so I don’t have a list-”
Mycroft finds himself on his knees beside Sherlock’s chair, wrapping his hands around Sherlock’s, and he isn’t entirely sure but he thinks he may be crying.
“Oh, Sherlock,” he says. “Oh, brother mine, there you are.”
Sherlock looks at him like he’s lost his mind and Mycroft shakes his head, asking for a moment without words. Sherlock untangles one hand and places it gingerly on Mycroft’s head, as though he’s not entirely sure what to do with all this emotion.
It takes five minutes for Mycroft to get his emotions under control and he gets back to his feet, and turns to face the fireplace/
“You know what’s happening to me,” Sherlock says. “You’ve been expecting this.”
“I know, yes,” Mycroft confirms. “As for expecting this? Hardly. I could say that I have…hoped, desperately, that this would happen one day, but I’m not entirely sure that the word covers enough ground in this case.”
Mycroft sits and studies his brother.
“When we discovered what Eurus had done,” Mycroft begins, and Sherlock stiffens almost imperceptably. Mycroft continues, implacable. “We did not immediately understand the full import. A child should not have been capable of what she did to you - there are people who train for years and are not capable of doing what she did to you. When I told you that you erased your memory of Eurus, that…was not entirely true.”
Sherlock raises an eyebrow.
“More lies, Mycroft? I’m really getting tired of these games, you know.”
“Sherlock, please. This is not a game, and I could not have told you the full truth. Not then, and certainly not in front of John. Will you listen?” Mycroft waits for Sherlock’s reluctant nod before continuing. “You did not erase your memory of Eurus. Eurus did that herself, and in the process, she did something else to you, something that the best minds in the world have not been able to understand or undo. By the time we realised how she had blinded you, the effects had sunk in and you were actively resisting any attempt to undo it.”
“Blinded me how? Stop talking around it and get to the point, Mycroft!”
Mycroft sighs heavily and takes something out of his breast pocket. A long, thin stick, which he waves in the air. Between their two chairs, a small table appears, bearing a tea service and several small, delicious cakes.
“Can you see that, Sherlock?”
Sherlock is almost crawling up the back of his chair, staring at the table in horror.
“What…what…” he opens his mouth a few more times, but nothing comes out.
“There is a world beyond the one we live in, Sherlock. Beside us, every day, invisible and unseen. You were meant to be a part of that world, but when she attacked you on the night she burned Musgrave to the ground, Eurus not only erased every memory of herself, but every memory of the world we were born to, and blinded you entirely to its effects. Three years ago, Sherlock, I could have done this in front of you and you would not have reacted. Your mind would have filled in the blanks and created a story you could believe, because it had lost the ability to see this.”
Sherlock still looks horrified, and Mycroft wonders if he should continue.
“I believe that when you confronted Eurus in the prison and at Musgrove, some of the things she had done became…damaged. And they are being damaged further-”
“The point, Mycroft. Please,” Sherlock bites out, and Mycroft sighs again.