"Who taught you?" Charlie asked. His expression was a mixture of astonishment and, strangely enough, exhilaration. No one in his family or friend's circle would play chess with him anymore, and he had stopped asking.

Kai had shown up an hour ago with questions concerning the day's lesson, while he was working on something for Don. At the sight of Charlie's upheld finger, they had taken to strolling through the office silently. Kai was so quiet, in fact, that Charlie thought they had left. He startled when he caught movement from the corner of his eye. His student had picked up a chess piece from a dusty, set up board, and was studying the black queen. There was an expression on their face Charlie had never seen before. It was disconcerting and… a little gut-wrenching, he had to admit.

Without thinking, he had set his marker down and invited them to a game. Sure, it would be predictably boring, but maybe it would be a way of getting to know Kai better. After five months in his class, Kai was still as much of a reticent enigma as when they walked into his office for the first time. He hadn't missed the way they deflected personal questions or any inquiries that so much as toed the invisible boundaries they set. The game, however, had been anything but tedious. They were still attempting to checkmate each other. "My father taught me."

"How old were you when you started?" Charlie asked while eying his pieces and making a move, glancing up at Kai after.

His student tilted their head, attention rapt on the board. He noticed they did this when considering a particularly interesting problem or explanation in class. The gesture made him unconsciously smile. "Young. Probably four? Five?" Kai replied. Charlie's eyebrow rose at this. When he didn't speak, Kai glanced up and noticed the questioning look. "I was a precocious child. Not so much in numbers, to my parents' dismay," they said with a hint of a smile.

The implications of their comment surprised Charlie once more. "Your parents are mathematicians?"

Kai let a hum escape as affirmation before picking up a knight and making their move. It'd been such a long time since they played chess for fun. And Charlie was fun. "My mother's in Applied Mathematics. My father, Astronomy," they said casually, and glanced up at Charlie after, curious as to his reaction. They chose their words carefully despite their relaxed delivery. His eyes were on Kai.

"That's why you're here," he said after a minute. Kai picked up signs of understanding and the not-so-subtle hints of guilt. "You want to know them. Or at least know how their minds work, right?" He lowered his gaze

"That's the ticket," Kai replied with a small smile.

Charlie frowned, seeming to examine the board, though it seemed more to Kai that he was looking straight through it instead. He was struggling with something, and Kai was positive it wasn't their current chess game. He's trying to figure out how to ask, they realized.

"Why don't you just talk to your parents?" Charles finally said, ignoring the game and looking back up at Kai once more. Before they could speak, Charlie held up a hand. "Look, I get it. Trust me, I get it. Family, they can be hard to get along with or understand. I'm not pretending to know your current situation either. But, it's obvious to me you want to know them. So it's safe to assume you don't hate them or wish to keep distance with them. And I'm sure they would love to share about themselves with you."

"Professor… Charlie," Kai amended. "I appreciate your concern. Truly. My particular situation, though, is… Well, as cliché as it may sound, it's a long story. And I neither have the time nor the desire to go into it."

"You remind me of my brother," he said with a slight chuckle.

Kai's features twisted at this. "I was starting to like you, professor," they replied. "I cannot believe you've insulted me so deeply."

"He really isn't a bad guy, Kai," he said with a real laugh now. It didn't escape either's notice that it was the first time the professor had called his student by their first name. His eyes averted back to the board, considering just for a breath, before moving a piece. "Just like I don't think you're a bad guy either. Sure, you're both annoyingly stubborn, wary of others, constantly playing things close to the vest. But, that's not bad."

The sound of a cell phone interrupted any response Kai could give. Charlie gave them an apologetic look as he searched his pockets for the device. "No worries, professor. It's late anyway. Pick up tomorrow? No cheating," they added with a smile.

"That's a deal," he grinned, finally pulling out the cell phone and giving a quick glance at the screen. "Hey, dad." The two stood, Kai heading for their discarded book bag and Charlie reaching for his backpack. "Yeah, I'm heading out now. I got caught up with Kai. My student," he clarified. "I'll see you in a bit. Okay, bye."

"I'll walk with you, if that's alright," Kai said.

"Yes, that's fine," Charlie nodded. "Have you ever competed professionally? In chess, that is."

"No. It's simply a fun pastime. The idea alone of competing makes me uneasy," Kai explained.

"Really? Competition makes you uneasy?" Charlie chuckled as they started walking out of the building. He wondered what they thought of the way they interacted with his older brother. When he thought about it, confrontation was just another form of competition. This one involved the pitting of their wills against each other. He decided it was better to keep that to himself, though.

The night air hit the two as they stepped out onto the campus, the sweet smells of spring in full bloom. "Despite what you've seen, I'm very much not the confrontational type," Kai laughed embarrassedly, as if reading Charlie's thoughts. "I keep to myself, for the most part. Millie can attest to that."

"I've seen it," Charlie assured with a smile. "In class, at least. You don't speak up or ask questions, you never interact with other students, you wait until everyone leaves before you even get up…"

"My, you've certainly been watching me," Kai said with a laugh, though the sound was a bit uncomfortable. "You're reminding me of Millie."

"Are you comparing me to my boss because I compared you to my brother?" Charlie joked as the two walked down the first flight of stairs.

He was expecting a smart reply and when it never came, he noticed Kai's attention was elsewhere. Charlie's attention brought theirs immediately back to him. "Dr. Eppes, out of curiosity, how far would you say the campus security is from our current position?" Charlie was used to confusing people with what seemed like disconnected associations to others, and he fleetingly thought this was probably what others felt when he spoke.

"Campus security?" he echoed, scratching at the back of his neck. "I'd say about half of a mile?"

"And about how fast would you say you could run a mile?" Kai's eyes were on Charlie now, a smile on their lips. Except, Charlie noticed, it didn't reach their eyes. The look he saw there made him uneasy now.

"I mean, the last time I ran a mile, keeping a consistent pace, it took me about twenty minutes," he replied as they started down the second flight of stairs. "And the last time I really pushed myself, it was probably around fourteen to sixteen minutes."

"It'll have to be good enough. When I tell you to run, you run, professor," Kai said, the smile still on their lips. Their book bag was gripped in both hands before them now, Charlie noted, and their knuckles were white. He was about to speak again when Kai cut him off. "We don't have time professor. There's a man walking straight to us. There's empty space all around us and this man is walking right. At. Us," Kai said, their voice now almost a hiss as the words came through their smiling teeth. "When I say run, you run."

It was when they hit the landing that Charlie turned and spotted a man just a couple of feet away. His hand was in his jacket's pocket, bulky. A clenched fist, maybe? Too big. It had to be –

The thought was interrupted when his line of sight was blocked. Kai had somehow closed distance with the stranger, their book bag arching through the air and aimed straight at the temple of the stranger. "Run, professor!" Kai screamed as the book bag connected with a loud thud, and a shot went off even as the stranger was knocked off balance. There was no gun in sight, but the sound was unmistakable. Charlie couldn't seem to command his legs to move, though. "Charlie! Run, dammit!" It wasn't his name that broke him from the paralysis. It was the mixture of raw fear and pain in Kai's voice that freed him.

He understood a little too late, the reason for Kai's questions. His feet slapped over the pathway, backpack thumping against his back as a stitch started to burn into his side, but he didn't dare stop. The campus security kiosk came into view and he screamed before he reached it, waving his hands in the air. A night cop came out to meet Charlie and he relayed what was going on through harsh breaths. The guard took off in the direction he pointed, gun drawn, and Charlie followed, albeit at a slower pace now. His phone was in hand, dialing Don as he headed back to the spot he'd left Kai in.

"Hey, buddy. What's up?"

"Don, we were shot at!" Charlie cried into the phone, trotting now as he came to the area where he had left Kai. His blood ran cold when he noticed the empty space. Empty, except for a puddle of blood. "Where are they?" he asked the security, frantically circling to search his surroundings. The security was speaking into his radio, his own eyes set on the asphalt. "Oh, God."

"Charlie? Charlie! What's going on?" Don's voice was a bark now, tight with worry. The professor could hear his brother scrambling on the other side. "Are you hurt? Is anyone hurt?"

"Someone took them, Don," Charlie choked out. "They took Kai."