The jet hummed low as it cut through the sky, evening light spilling gold across the windows. Spencer sat hunched over the small chessboard stretched between the armrests of the leather seats. He barely blinked as he moved his bishop, lips pressed tight in focus. Gideon, quiet as always, studied the board like it might whisper secrets to him if he waited long enough. Spencer didn't wait. He turned toward the figure slouched beside him, his sister, younger by barely a year, but sharper than most agents who carried badges.

"You know statistically, if you open with a queen’s gambit, you're playing into your opponent's center control, but Gideon insists on starting with it anyway," Spencer said, voice quick, words tumbling over each other like dominoes. "I mean, it’s technically sound, but it gives too much away early on. He knows I know that. So now we’re both pretending it’s a bluff, but it isn’t."

She raised an eyebrow, but he kept talking. His fingers hovered over the pawn he'd moved just two turns ago, like he needed to physically keep track of the game's momentum. "Also, did you know the Soviet chess champion Mikhail Tal used to intentionally smoke during matches just to psych his opponents out? He had a photographic memory, but the smoking, " he glanced up at her, a flicker of a grin, ", that was psychological warfare."

Gideon moved a piece. Spencer didn’t look. His gaze stuck to her face like he was waiting for her to challenge the fact, or maybe roll her eyes like she always did when he talked too fast. Instead, he dropped his knight into place and leaned back with the self-satisfaction of someone who knew he was still three moves ahead. He crossed one leg over the other, socked foot twitching slightly.

"I don’t think they get it," he said. "They see the IQ scores, the degrees, but not the rest. They don’t know what it’s like to have your brain running faster than your body can keep up. I had to get my firearms qualification signed off three times. You, what, tripped during the obstacle course and still beat half the class?" He nudged her knee gently with his. "They still think we’re going to get dropped off at a library and forget to come back."

Gideon leaned over to consider the board again, silent as ever, but Spencer didn’t seem to need his attention. He only needed her, the one person on this plane who understood that being brilliant didn’t mean being respected. Or safe. Or normal. "You know, I calculated the odds of two siblings both having prodigious cognitive profiles and still ending up in the same federal task force. Less than .003 percent. And that’s not accounting for the nepotism we didn’t benefit from." He frowned suddenly. "Wait, are we nepotism if we’re the same rank?"

He blinked, then shook his head like a dog shaking off water. "Never mind. Irrelevant."

The jet jolted slightly from turbulence. Spencer flinched, not because he was afraid of flying, he wasn’t, not since he memorized all the crash statistics, but because his balance had never been great. Neither was hers. He glanced over, subtly checking that she was okay. She looked unbothered. Of course she did. She always looked calm right before saying something that would completely unravel whatever theory he was working on. He liked that about her. Hated it, too. Mostly liked it.

"Do you think if we both disappeared off this jet mid-flight, they’d notice before landing?" he asked, almost too casually. Then added, "That was rhetorical. I already ran the probabilities. JJ would notice in 2.4 minutes. Morgan wouldn’t until we missed the briefing. Hotch might think it was a team-building exercise. Gideon, " he lowered his voice like he was sharing a state secret, ", would notice the moment no one’s here to play him."