[AN: I wasn't sure how to begin the story, so I just jumped right into the middle. Basically, Sherlock and John chase a murderer into a flat. Said murderer kills the woman who tries to stop him and escapes through the open window.]

"John."

"Yes?"

"Come here." Sherlock said, motioning for him to come closer.

John frowned. Sherlock was standing over a crib, his face blank.

"Oh god," John thought. "Please don't let there be a kid in there."
He walked over slowly to Sherlock's side and peered in. He let out a sigh of relief. There wasn't anything gruesome inside. There was, however-

"It's a baby." He said.
"A brilliant deduction, John." Sherlock said, shooting him a sideways gare.

The baby was latino, all brown eyes and poofy hair. He stared up at the two men, curious but quiet, ignorant of his mother's murder.

"How'd he get here?"

"I think," Sherlock said, gesturing to the body sprawled on the floor, bleeding out into the carpet, "That its mother put it there. Do keep up."

John rolled his eyes. "Okay, but what what should we do with him?"

"Lestrade should be here in approximately 19 minutes. It should be fine on its own until then." He said, turning towards the window with a wave of his hand.

"Sherlock!" John said.

The baby sucked the sleeve of his blue dinosaur onesie.

"Hm?" Sherlock hummed, scanning the open window.

"We can't leave him here!"

"In case, you haven't noticed, there is a murderer with the Seitenna diamond running through the streets of london that needs our immediate attention." He said, without looking up.

Just then, the baby started to cry.

"I'm not leaving him." John said, bending over to pick up the now-wailing baby. He bounced him a bit until he stopped crying.

"John!" Sherlock said, striding over to him. "This is a crime scene. Don't move things, it breaks my concentration!"

John glared. "He is not a thing."

Sherlock closed his eyes and took a breath. "John, I recognize that you are acting upon your base parental instincts, but I need you to be rational. The child's other parent could come home any moment, and I'm not sure that we'd give a very good first impression"

John continued to stare defiantly at him.

"Fine." Sherlock conceded. "Just don't put it down anywhere! Help me examine the body."

John sighed. "Here, hold the baby." He said, pushing him into Sherlock's arms. The man made a startled grunt, but didn't drop him. Satisfied, John bent and took a closer look at the woman's prostrate form. "There." He said, pointing to the gash running along the woman's jugular. "The same distinctive nick. He used the same weapon here as he did on that librarian. I'd say he used a..." John straightened to look at Sherlock. "Bayonet, most likely not mounted on-" He stopped.

The baby was staring at Sherlock, a mesmerised look on his face.

"Hm?" Sherlock said, turning back to face John.

"You..." John shook his head. "Make that face again."

"I was not aware that I was making any strange faces, John." He said, giving the baby a small bounce.

"You went cross-eyed! I saw you!" John said, trying not to laugh. "Standing in someone else's flat, playing with the dead owner's baby. Dear god, this is so messed up." He thought.

"I did nothing of the sort." Sherlock said with a sniff, pretending to scan the windowsill again.
The baby smiled and giggled, opening its mouth wide to reveal its pink gums.

John watched as Sherlock tried to battle the smile that threatened to take over his face. His efforts were fruitless, however, and John had to cover his mouth to keep from laughing as Sherlock's face widened into a huge grin.

"I think he likes you!" John said, on the verge of some very un-manly giggles.

"Oh shut up!" Sherlock said, his smile replaced with a look of angry embarrassment. "I'm texting Lestrade."

John just shook his head and watched as Sherlock moved around the room, scanning things and giving the baby an occasional bounce.