Summary: At the end s09e03 (I'm No Angel), Cas tries to leave discreetly in the early hours of the morning only to run into Sam.
Right Here
It's barely dawn when Sam heads for his morning run and bumps into Cas, fully dressed and with a knapsack, on his way out the door.
"Cas?"
"Sam." He turns, a small smile on his face.
"Where are you headed so early?"
Cas looks away. "I… I can't stay, Sam."
Sam blinks, his face a mask of incomprehension. "What? Why?"
Shifting the bag on his shoulder, Cas explains, "They're looking for me, Sam. They found me before. If they find me again here…"
"Then what?" Sam challenges. "This bunker, it's the most defensible place we know. If you're not safe here, you're not safe anywhere." He takes Cas by the shoulders, eyes pleading. "You can't go back out there, Cas."
"Sam? Cas?" It's Dean, shuffling out in his robe and slippers.
Sam turns. "It's Cas, Dean. He's leaving. You know we can't let him back out there." He looks expectantly at Dean for back up because Cas tends to listen to Dean.
To his surprise, Dean doesn't meet his eyes. "He's right, Sam. He can't stay."
"Seriously?" He looks from Dean's awkward face to Castiel's wistful expression. Cas turns to leave, but Sam doesn't let go. "Dean. We almost lost him just yesterday. You can't send him back out there, Dean. You can't."
"Look, I don't like this any more than you do, all right? But if he stays, all those angels," Dean gestures expansively, "are going to come looking, and we can't stand against an incursion, Sam."
"I know that, Dean. I know that. But it's Cas." He shifts his hold to grip Castiel's hand and lace their fingers. "You said so yourself: you, me, Kevin and Cas, we're all we've got in this world now."
"You're not hearing me, Sam. If Cas stays, you die. Maybe we all die."
"No, I hear you, Dean. I do. But we're in this together. We'll figure something out, Dean, like we always do, but I won't let you send Cas out there alone."
Suddenly, Sam's eyes glow blue, and his posture shifts. "I'm sorry, Dean," he says, but it doesn't sound like Sam, and Cas has heard that precise manner of speech before. A long, long time ago.
"No!" Dean reaches for not-Sam. "Zeke, wait. Wait!"
But Sam's body glows, and the light flows out of him. Cas gasps in shock. Because Ezekiel. Oh. Oh.
When the light fades, Sam staggers back, and Cas quickly moves to catch him.
"Sammy!" Dean rushes to his brother's side to help hold him up. "Sammy?"
"I'm fine." Sam waves weakly as they lower him to the floor. "I'm just...really dizzy all of a sudden."
Looking at Dean's anguished face, Cas suddenly understands, and he shifts his hold to cradle Sam in his arms, close to his heart.
"Don't leave, Cas." Sam reaches up to touch Castiel's face, brush away the tears with his fingertips. It's a strange sight. He's never seen Cas cry before. "Promise me."
"Of course." Cas smiles reassuringly. "Never, Sam. I'll be right here with you."
Sam smiles up at him, then turns to Dean. "Don't make Cas leave, okay?"
Dean forces a smile and nods. "Okay, Sammy, okay. We're all gonna be right here when you wake up, okay?"
Sam nods and closes his eyes, and Cas just tightens his hold on the younger man. He's never felt so sad before. Not even when the angels Fell.
