A knock on the door caught Sherlock's attention. When he opened it a distressed couple walked in. "How can I help you?" He asked as he saw their hesitation. "Mr. Holmes. We know you don't take cases like this but our neighbor-" The woman started with a sob as her husband tried to calm her down. "He's a bad man." She continued with and shook her head. "But we don't know how to proof it." The older man said, Sherlock could see that they wanted to help but were simply too afraid of the consequences to do so. "What exactly has he done?" Sherlock asked and mentioned for them to sit down.
An hour later Sherlock took a taxi to the given adress, John in his company of course. "Are just just going to knock on the door?" John questioned with a frown. "Yes." Without questioning further John nodded.
Sherlock banged on the door as a very angry man opened it. "What the hell do you want?" He asked, clearly drunk. "We're here to see (Y/N)." Sherlock said sternly not wasting any time on small talk. After doing some research he had found out your biological mother's name, it was a name Sherlock would never forget. And according to your birth date it would be at the time he met her. It didn't take long for him to draw the conclusion that you were his daughter, but he needed to see it, he needed to see you to know for sure.
The man, too drunk too care, called down the little child. Instantly the similarities between himself and the child was shown. "(Y/N). I'm Sherlock Holmes." He smiled down at the child as John's eyes went wide once he realized what was happening. "I'm here to take you away from this place. You're going to live with me and John from now on."
It took a time for Sherlock to understand what he was doing but after a week it all went by smoothly. He would read to you before you went to bed, play the violin for you and of course cuddle. It was comforting for him to have you there which made it all so much easier. And with help from John it was even easier. It was almost as if the two of them were destined to be parents.
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Just published the first part of my Johnlock fanfic. Make sure to check it out and don't for get to comment if you have more requests.