Cain was watching a movie with Jeb when he heard the loud thump through the living room wall.

It had only been a week since they had moved into the apartment, but there was a partying 20-something year old to their left and a football fan right across, neither of whom had bothered them much. It was already evident that the walls here were considerably thicker than the ones at their last place; which meant whatever had just happened in their other neighbor's side of the wall must have been serious.

He had been only half paying attention to the screen before, but now his eyes were fixed on that bare expanse of wall, waiting for anything else.

"Turn that down..."

Jeb took the remote and did as he was asked, even as he kept eating popcorn and glancing curiously at the wall. "What do you think that was?"

"No idea."

A minute ticked by, then another, and Cain was almost about to let it go when the same muffled but loud sound rang from the other side; like a faint explosion. When it happened again, faster than the other times, Cain stood up quickly and went to get his gun.

"Stay here." He told Jeb as he tucked the firearm under the waistband of his pants, and then he was out the door.

Thinking back on it, maybe taking his service weapon was a little excessive. After all, this was a much nicer apartment building where precisely this type of thing didn't happen, whatever this thing was, but Cain had no idea what could be the cause of the noise and it was better to be safe than sorry. Even if Jeb might mock him later for 'always thinking like a cop'.

Now that he was standing in front of his neighbor's door, knocking calmly and waiting patiently, he realized he had never met or seen the man.

"Everything alright, Mr. ...?" Or even learned his name.

He was just 'that guy in 120A'.

Cain was starting to get antsy when the heavy door swung back to reveal a man around his age, skinny, and with wild curly hair framing his grinning face.

"Good morning, how may I help you?" he asked sweetly,

"Actually, it's almost midnight." Cain said, taking a closer look at his mysterious neighbor.

He was nearly Cain's height but far thinner and paler, and—despite the fact that he sort of looked like a mad scientist with that hair and that coat—there was an innocent gentleness to his brown eyes that told Cain he wouldn't need the gun for anything with this guy.

"Oh, I could have sworn it was morning just a moment ago." He frowned slightly in confusion, only to smile again in an instant, "But there you go, time flies when you're busy!"

"About that," Cain started, partly amused but trying to be serious, "sorry to ask but what was that—"

With the door open, and nothing to silence the sound but the other man's lithe body, the loud bang that resonated into the hallway was indisputable this time.

"That noise."

"Oh dear," his neighbor said as he looked back over his shoulder at the room.

"Please tell me that wasn't really a bomb." Cain sighed, his face buried in his palm, "I was having a good week."

"It was not a bomb!" the man said indignantly, "What do you take me for, some kind of madman?"

He wasn't that far off. "But if it wasn't a bomb then what?

"It's just my latest invention," he said with an air of defeat, "I was going to keep working on it but if it's really that late I'll turn it off."

"Good. Thanks..." Cain shifted awkwardly, feeling inexplicably disappointed that the conversation seemed to be drawing to an end. His odd neighbor was already turning back inside, when all of a sudden he perked up and snapped his fingers at Cain.

"Wait a minute! You're the new neighbor aren't you? Right to my right?"

"Your left."

"My left, got it." He nodded to himself absentmindedly, "Well, this was nice! You should stop by for coffee and cake some time—unless, you know, one of my machines is causing minor explosions again."

"I don't even know your name." Cain chuckled,

"Dear Tesla where are my manners! My name is Ambrose," he extended his arm, "Ambrose Gale."

"I'm Wyatt Cain," he said as he shook his neighbor's, Ambrose's, pale hand. "And I might take you up on that offer sometime. Except uh," he cleared his throat, "I'm not bringing my son near your machines, no offense."

"None taken! Though I'm sure my nieces would love to meet him."

"So you don't have kids? Or a wife?" he prodded,

"No, with my job I wouldn't have had time for kids of my own. And women were never... My forte." He smiled, but there was something decidedly not innocent about it this time. "But I suppose you're more settled in than me?"

"It's just my kid and me, new job, new high school, new town," Cain shrugged, "You know how it is."

"Yes," he nodded slowly until it turned into a shake of the head, "No. I don't really; I've lived in this town almost all my life. But you can tell me more about it over coffee someday?"

"And cake?"

"And cake."

Cain's lips slowly curved into a smile; more and more interested in getting to know his mad engineer neighbor with each moment they spent talking on his doorway.

Which of course had to be ruined by another 'minor explosion'.

Ambrose winced, "I should probably go now... It was really nice to meet you, Wyatt. Call me if you need anything!"

And with that, the door was shut and Ambrose gone behind it; too quick for Cain to even react.

The short walk back to his own apartment felt longer than it should have as he tried to figure out what had just happened and if it meant what he thought it meant. But for now, he was back in his side of the wall, where Jeb had casually gone back to watching the movie without him.

"What if it had been a psychopath and I had been kidnapped?" Cain asked as he put his unnecessary gun away and sat next to Jeb.

"I'm the one who found this place remember?" he said through a mouthful of popcorn, "There's 99.9 chance that stuff like that won't happen around this side of town, but you're a cop so you always see that .1 chance."

"Fine. Still, don't you want to know what it was?'

"Sure, though I'm more interested in the fact that you met someone." Any other time that would have been a perfectly common statement, but the way Jeb wiggled his eyebrows suggestively when he said it was like he just knew what Cain had been thinking on his way back. "Boy or girl?"

For a moment he just stared at his son, mouth hanging slightly open in surprise, before answering, "Boy... You'll make a great detective someday, son."

"Nah, I can just read you like a book." Jeb smirked, "So this guy, what's he like?"

"Honestly I've only just met him." Cain said as he stole some popcorn and turned on the volume to hide the minor explosions from the other apartment, "But at the very least he's one hell of a neighbor."

A/N: This was just a silly thing written for the prompt "One of them moves in as a neighbor" from a random slash prompt generator XD But I'll probably write more.