Dean doesn't hear Sam sit up — doesn't look in his rear view mirror right away. He's too focused on the task ahead, scanning areas to find a safe place to burn Sam's body.

Then he hears his name.

Dean doesn't jump. He doesn't react with surprise or jerk the vehicle to a stop. Instead, he calmly looks in the rear view mirror, sees Sam, and then pulls over.

Nothing surprises him anymore.

Obviously, a bullet wasn't enough to keep Sam dead, so whether this is the Sam of an hour ago or something supernatural coming to mock Dean for being sentimental and hanging on to Sam's body long enough to give it a proper hunter's funeral — well, it doesn't matter. Either way, a gun isn't going to provide him with much defense.

Dean isn't a fan of going weaponless in situations like these, though, so he ultimately pulls out the pistol anyway. He doesn't aim it, though. Just holds it in his hand as he turns around to get a good look at Sam.

He doesn't feel anything. There's no relief, no shock, no grim sense of joy. Dean's fresh out of emotion, so he settles on saying: "You're really gonna make me ask?"

Because if Sam's going to wake up from the freaking dead, the least he can do is explain what the hell is going on.

Or offer up his arm so Dean can perform the necessary tests.