Chapter One. The Child.

Baker St. Come quickly. An anomaly has risen. - SH

This was what John woke up to late Wednesday morning. No explanation. No context. And knowing Sherlock Holmes, a text like this could mean anything.

What do you mean? What's wrong?

Just come - SH

The problem with this request, unfortunately, was that John had been left in charge of his daughter for the day. Mary wasn't due back until the afternoon.

But I've got the baby.

NOW - SH

Cursing to himself, John pulled himself out of bed and rushed to get himself ready. Whatever it was, he assumed it was important if Sherlock was bothering him on one of his 'do not disturb' days. Or at least, it better have been, since he'd have to take Sherry with him.

Struggling to slide on a pair of slacks and cross the room at the same time, the war doctor leaned over to look down at his three month old still fast asleep in her crib. She had woken up in the middle of the night and for hours had refused to go to sleep. Hence why it was almost noon and the two of them had still been in bed. Poor Mary had almost canceled her day out with Molly because of Sherry, but he'd managed to convince her otherwise.

Buttoning his trousers, John smiled at the sleeping baby before moving to fetch her car seat. "Looks like we are going to be taking a day trip," he said softly, an apology in his voice as he set the seat on the bed and found himself a shirt. "Uncle Sherlock needs us, apparently," he added with a roll of his eyes, buttoning the last of the buttons and fixing his collar.

After running his hand through his hair, he carefully picked his daughter up, in the hopes of letting her sleep a bit longer, and carried her over to the changing table. With three months being an adequate amount of time to learn how to change a baby without waking her, it didn't take him very long to put on a fresh diaper and switch out her pajamas from something more appropriate. When that was finished, he transferred her into her car seat and buckled her up.

"I know, I know," John sympathized when the baby made a small sleepy noise of complaint at being moved. He waited a beat, letting her get settled and drift back into a deeper sleep before he lifted the seat by the handle and took her into the living room where he began to collect her diaper bag and got her premade bottles out of the fridge.

A few minutes later they were out the door and in the car in such a rush he nearly forgot to buckle her in (god, don't tell Mary). The traffic to Baker St wasn't too terrible (at least by London standards), and so it wasn't long before John was making the trek up the steps to the flat, car seat in one arm and diaper bag in the other. Not needing to knock due to his spare key, he was surprised to find that the door was already unlocked and nudged it open with his foot.

"Sherlock, I-"

Before he could even get a sentence out, John frowned at the sight of Sherlock staring unblinkingly over steepled fingers at a young redheaded boy sitting across from him in the war doctor's usual seat. Serlock's gaze was intense, as if there was a puzzle right in front of him and he was determined to solve it. He looked ridiculous, though, since he was still dressed in his dressing gown and hadn't bothered to even try to comb his bed head.

The boy, on the other hand, stared back with no signs of being uncomfortable… he looked almost to be studying the detective, trying to figure him out as well. Held tightly in his hands was a backpack.

Neither moved from their little staring match, not seeming to register John's entrance.

"... What's going on?" He asked carefully, walking over to set Sherry down on the coffee table. He didn't receive an answer, and after a few moments of silence, he added a "Sherlock?"

At this, the detective blinked out of his concentration and turned to give his friend a look of confusion. "John? What are you doing here?"

If possible, the man's frown deepened. "You texted me. Asked me to come."

"Did I?" Sherlock questioned and then glanced down at his phone as if he hadn't realized it was clasped between his hands. "Ah yes. So I did." He acknowledged but made no move to explain himself as he pocketed the device.

"So then?" John pressed, becoming a bit impatient.

"Hm?"

He jerked his head toward the boy. "Who is this?"

As the man's eyes fell back on the child, they started to glaze over as he made a face. "Ah..." The look wasn't necessarily disgust, but it was by no means pleasant.

"Well?" John continued, definitely impatient now.

"What is your name?" Sherlock asked as if the thought had only just occurred to him.

The boy frowned, blinking as his eyes fell to his shoes. He didn't answer… but it didn't seem to be out of shyness. Whatever it was, it was clear that he wasn't going to say a word.

John found this whole predicament strange. Some random kid just shows up to Baker Street unsupervised and unwilling to explain himself… It just seemed… off. Why was there a child here of all places? Where were his parents?

Wait...

"Sherlock please don't tell me this is-"

"For god sakes John, no. He's not my illegitimate son. Does that look like my nose?" He snapped feeling very much offended.

No. It didn't. He was right... but the kid did look as if he could pass for a Holmes.

Well, a ginger Holmes. ...If a Holmes even came in ginger. The curly hair. The long nose. The sharp blue eyes that seemed to take everything in. It couldn't be a coincidence.

The boy turned to finally give him an inquisitive glance and it was brief, but for a moment he saw someone else in him.

"Well, he looks an awful lot like-"

"Mycroft," Sherlock finished, clearly thinking the same thing as he leaned back in his seat.

"Ah yes, My- wait what?" He cut himself off, realizing that if Sherlock was agreeing with him on an observation that the boy didn't just look kind of like the older Holmes.

With a sigh, the detective reiterated the comment as he waved a hand lazily, "This child holds a striking resemblance to my brother."

There was a beat as the doctor let the information sink in, and then, "...I don't understand."

"What do you not understand?"

John shook his head, needing to take a seat on the couch to process further. "No. I mean, that's not... That can't be possible. Right?"

"It's very possible."

John honestly couldn't wrap his head around this. He couldn't see either brother ever getting intimate enough to sire a child. Especially Mycroft. "How?"

Sherlock looked at him indignantly. "...You know how a baby is made, clearly."

John frowned at him, knowing he walked right into that one. "That's not what I meant…" Looking back at the child in question he shifted uncomfortably. "So, does he know?"

"Unlikely, given I didn't know until moments ago," Sherlock said with a strange calmness.

"I... S-Shouldn't you call him?"

Sherlock made another face.

"I mean, if it- If there's a possibility…."

"And say what John?" The detective dismissed, standing up with his usual abrupt flourish. The child looked up at him questioningly. "No… we must be sure first."

At this, it was John's turn to sigh. Something told the good doctor that he wasn't going to like where this was going.

A/N: So I had this idea brewing before the events of season 4, and as such it's likely it won't be incorporated… or at the very least it will be altered to fit the story's needs. We shall see. For example, you may have noticed that the baby is referred to as "Sherry" that is because before we knew the baby's name I thought it would be cute if despite John having said he wouldn't name the baby after Sherlock they did still pay homage to him by giving her a variation of it. That said, I do love the name she was given canonly and so her full name is Sherry Rosamund Mary Watson.

Anyway! I hope you enjoyed this!