This takes place at the end of 5x13.
He's thinking to himself as his gaze lands upon her that she's got to be the most enigmatic thing he's ever seen. It surprises him that she is, because if someone were to enter the great mind of Dr. Spencer Reid they'd be nothing short of astonished - what with the hundreds of thousands of things he's seen, places he's been, words he's read and heard from the tattered old books his mother used to read him. Images of Emily Prentiss floating amongst these wondrous pictures would be nothing if not bland to the ordinary mind, but to him they are the most special.
She's sitting across from him, crouched forward with her elbows leaning on the table that's separating them, and she's holding some sort of puzzle in her hand. With focused eyes and eyebrows knit together in intense concentration, she continues her attempts of solving it. She spins the puzzle around again in her hand and reexamines it, her fingers beginning to twitch from her efforts. He's come to learn that she's the most determined of the team, stopping at almost nothing when there's at task at hand and she's set her sight on accomplishing it. This would be her forty-second try at solving this one; he's counted.
Finally his curiosity gets the better of him and he asks, "What is that?"
"It's called a star puzzle," she answers him almost instantly, as if she knew that he was watching her and was waiting for him to question it. Her eyes only meet his for a moment before she shifts her focus back onto the broken star in her hands. "It's basically impossible to figure out. You have to put all of the pieces back together to form a perfect star," she adds while her eyes remain fixed on the puzzle.
He can feel Rossi's gaze on him before he sees it. His eyes flick to his left to look toward the older man for a second, and he finds that his inkling was correct - Rossi's eyes are trained on his, and he doesn't blink or avert his gaze even after Reid returns his attention to Prentiss. The profiler smiles subtly, but knowingly, before he himself turns his head back to face her. Part of Reid knows what the look means, but he doesn't allow his thoughts to linger on it for long -he only takes one more glimpse Rossi's way before looking back to Prentiss just as she's lifting her gaze to meet his in the middle.
"But the origin of it is uh," she looks away briefly, "kind of a romantic tale."
She smiles for a moment and places the star on the table, leaning back into the cushion of her seat. He shifts uncomfortably at the suddenness of having a conversation with her about romance, but he can't tear his eyes or attention away from her long enough to escape it and has no choice but to listen.
Morgan pulls off his headphones as she begins to tell the story. Garcia stops knitting from behind her, Rossi is now facing her completely, and even Hotch has perked up a little bit from the back of the plane - but it's almost like she's completely unaware of the sudden audience she's gained. She doesn't even acknowledge the rest of the team, and instead looks at him and only him, and she seems to be telling the story to him and only him as well. Her eyes avert to reference the star puzzle on the table, but when she's not looking at that, her gaze is locked with his.
His unblinking eyes remain on her for the beginning of the story, watching her lips move, her hands flow, her shoulders shrug. As she begins gesturing to the star on the table he too begins to steal glances of it, and before he knows it he's gathered the pieces in his hand and has begun examining them. It doesn't take long - maybe ten seconds - for him to figure out how to reassemble it, but he knows that she wants to solve it herself and resists the urge to put it back together. For her sake he places the pieces back on the table, fully intent on letting her struggle through it, as she's finishing the story.
He admits to himself that the story was intriguing - but then again, he thinks, nearly every word that she speaks has a way of peaking his interest. Although he knows it's just a story, he can't help but to point out the impossibilities of it. Part of him does it just because that's what he always does, but part of him does it so she doesn't know that he rather enjoyed it.
"It's not literal, Reid. It's a fable," she defends.
"But there's no moral," he responds instantly. "Fables have morals."
"Okay, so it's just a romantic little story," she gives in when she realizes he'd win the argument no matter what she were to say. "The point is it's basically impossible to do because…"
Her words begin to trail off as he remembers something she'd said when she was telling the story.
"So he frantically put it back together again to prove his undying love to her."
Before he knows what he's doing, he's picked up the pieces of the fallen star again and has begun reassembling it. A few seconds pass before he's finished, twirling it around in his hand to make sure it's complete before ever so gently placing back on the table for her, parallel to the story she'd told him.
She's trailed off and finally stops talking, transfixed by the image of the reassembled star sitting in front of her. It takes a moment for her to realize what's just happened, and when she does, she looks back up at him and says, "There's a lot to hate about you, Dr. Reid."
Morgan starts laughing and Garcia's trying to hide a smirk, but Reid's body stiffens at the words because for a moment he thinks that she's serious. But as everyone else looks down as they stifle their laughs, she looks at him and the corners of her lips lift slightly into a small smile that she intends for him, and only him, to see. He catches himself thinking that he'd disprove every impossibility in the world for her if it meant getting one of these smiles, one of these looks.
"Play poker with him sometime," Rossi tells her, his gaze shifting again to Reid who looks down once more as he suddenly thinks back to the look that he'd given him earlier. He realizes then that the older man knew before he did that he was in love with Emily Prentiss.
Ah, I love my Reid and Prentiss. I couldn't resist doing something with the wonderful scene at the end of 5x13, so this was the result! The subtle hints of Reid/Prentiss in it were pretty much begging to be more closely examined. It took me like twenty times to notice the Rossi gaze, but it was clearly there! That just makes me extremely happy for some reason..? I'm hoping the writers were hinting at the possibility of Reid and Prentiss, because if not then I'm clearly just overanalyzing everything. ;)