A/N: Psych isn't mine, and neither are Shawn and Juliet.

"You may say to yourself, 'my God, what have I done'?"

Shawn's head is spinning. That's not surprising. His head is usually spinning on cases, but usually that's because he's looking for clues and flirting with Jules and trying to convince Gus to spring for jerk chicken and bothering Lassie and thinking about what insight his dad might have on the case and watching a rerun of Phineas and Ferb in his mind, all at the same time. It's like a hamster wheel in his head, sometimes, going and going and going and never really stopping, sometimes even making that incessant squeaking noise like the wheel he had for his hamster, Sloth, (named for the guy from The Goonies, of course, that hamster really was astonishingly hideous) when he was nine.

Today, the hamster wheel is going like always, and it's squeaking like crazy. But the squeak is more like an alarm, an incessant beeping, like the one Gus sets and puts right next to his ear when he falls asleep in the Psych office in the middle of the day, or like…well, like those stopwatches he's been listening to all day. It's just there, the alarm in his mind, blaring behind everything, but especially right now.

He's looking at them, at Lassie and Mary—friggin' Mary, if only he really were Yang, that would've made things so much easier—and Jules. Jules. He knows his panic is written all over his face, but he doesn't care. He's terrified.

And then the plan is unfolding in his mind, developing even as he replays all the clues in his head, one of many trains of thought on the hamster wheel. He tries to arrange his expression so it looks less like fear and more like confident exasperation.

He's not sure if it works. But the plan is already in motion.

Shawn is going to betray them. Well, he's not, not really, if all goes well, but it's going to look very much like a betrayal, and if he weren't about to let Gus in on it, it would take about three seconds for Gus' Super Sniffer to smell the betrayal.

It looks like betrayal and it smells like betrayal, but it's not. Not really. Or at least that's what he's telling himself.

It's not that he's not a loyal guy, it's just that he gets distracted. His mind races sometimes, and it makes it hard to focus on anything. Sometimes that results in disloyalty, though usually it's disloyalty to a particular task more than a person.

Today, though, it's disloyalty to a person. Er, to a group of people, but Shawn is focused on one. It's strange how he has so much trouble focusing, until her. Shawn never struggles to focus on her.

Juliet is extremely loyal. Not in obvious ways; it's sort of a gentle encouragement that appears in her big blue eyes, pushing you onwards whether you're deserving of her support or not. It's an unspoken security—she has your back. She trusts you. Somehow, it makes you know, just know, that you won't, that you can't, let her down, even though she would still be there, inexplicably, if you did. Or at least, that's how it feels to Shawn. He can feel her trust in him almost tangibly sometimes, like a big fuzzy blanket tucked around his shoulders. It pulls him closer to her like a magnet while simultaneously keeping him from ever getting quite as close as he'd like to. And it terrifies him more than anything else, because she trusts him, and even as he lets her, he knows she can't trust him. He will let her down, and it will break her heart as surely as it breaks his, and the weight of knowing that, the thought of watching that encouragement die in her eyes, is killing him. It matters more to him than anything ever has in his life. But her eyes see none of that, they just lend her quiet support.

And perhaps it is this loyalty, more than anything else, that made him fall for her.

But he can't think about that right now. He can't think about anything right now, because his mind is moving too fast and his mouth is moving too fast and he is watching that support leave her eyes, watching himself kill it. She goes pale, her eyes flashing at him fiercely in a way they never have before, and he feels like his own cruelty is strangling him.

And the rest of the voices in his head are silent for a second, because suddenly the only thing he's paying any attention to is the fact that she is disappointed in him and he is mocking her.

He is mocking her. And it's a lie and he knows it, but as he spits the words at her, that maybe the next time she gets threatened, she can pick up her pom-poms and go for it all day long, he can see that she believes him.

She always believes him.

Usually this belief in him is what he holds onto; when his dad isn't proud of him, when Gus thinks he's being ridiculous, when Lassie won't even look at him, Jules always, always believes in him. He relies on that more than he realized, until now.

But she still believes him, and because she always believes him, he is hurting her. He knew he would, someday, but he didn't know how much doing so would break him. He watches the light and joy that are always in her eyes when she looks at him fade, and with it, her trust, her pride in him. He watches his hurtful words land, their impact as visible on her face as if he'd slapped her.

And even though he knows he has to lie right now, that it's the only way to get some space to solve the case, and even to keep her—and everyone else—safe, he hates seeing that loyalty gone from her eyes, replaced by fear and shock and disappointment.

He hates that he's the one who put them there.

So he turns away, where those eyes that usually look at him so generously can't reach him. But even as he does so, he knows his memory will never let him rest, will never let this new expression on her face stop haunting him.

He doesn't watch her go. He doesn't have to. That look on her face was enough to make whatever Yang has coming for him feel like child's play. And if he stopped to watch her go, he'd surely call her back. And none of them have time-not now. Not when Yang's stopwatch is already winding down.

So he turns to Gus, takes a deep breath, and the wheel starts moving again.

A/N: The quote at the beginning of this chapter, the title of the chapter, and the title of the story are from the song "Once in a Lifetime" by the Talking Heads (1981).