They stop for the night in Rock Springs, Wyoming on their way back home. If it were just Dean, he probably would have pushed it and kept going all twenty hours back to Kansas with a busted shoulder and stinging pain all up and down his body, but Sam reminded him that showing up at the bunker half dead and dying probably wouldn’t endear Cas to the idea of ever staying back and resting when he needs it again.
Also, with the state his baby is currently in, Dean’s worried she might not be able to handle the drive without a little break herself.
They get a motel instead of just pulling up in some seedy ass parking lot, because Dean reasons his baby deserves the rest stop. He also probably could use actually getting some sleep, too, but Dean doesn’t really want to dwell on the idea of sleep much recently. It’s hard to get much out of his already meagre four hours when all he can see flashing before his eyes is memories of Cas lying bloody on the library floor. Sam, though, he could really use the nap time, so Dean gives in and pulls up into the lot of the Rock Springs Inn.
He lets Sam check in, and takes the opportunity of being alone to call Cas.
Of course I’ll hurt you, of course you’ll hurt me. Of course we will hurt each other. But this is the very condition of existence. To become spring, means accepting the risk of winter. To become presence, means accepting the risk of absence.