Cas knows they can’t keep going like this. Every time there’s a lead, Sam insists they check it personally.
And Cas gets that. It’s Dean who’s out there, possessed by the most evil archangel of all time, worse even than Lucifer, so they can’t, don’t, leave following up on each sighting to anybody else.
There’s also the fear that if it is Dean, they’re handing a death sentence to anyone they send in their place.
But each sighting is a false lead, a case of mistaken identity, or it was Dean but he’s gone by the time they get to wherever he’d been.
This is wearing Sam thin, and Cas knows his hunter needs a chance to rest. To take stock and to recharge because when they do find Dean, and when they do rescue him, caring for whatever is left will take the rest of their lives.
It’s why he pulls in when he sees the old dirt road, turns down it carefully, ignores Sam’s puzzled, tired, questions, until he finds a clearing just big enough to take the car with room to turn her around, and stops.
“Cas? Cas we need to be home for tomorrow.”
“We will be.”
He gets out, pockets the keys, and goes around to the trunk. The old blanket is there, the one that’s been used for sleeping, for warmth, for comfort, and sometimes for this.
Cas spreads it down on the ground, and starts to undress.
Sam gets out of the car. “Cas.”
“I need you,” he says. “I miss you. Sam, please. There has to be something left for when we find him, and there won’t be if you don’t realise you need to be cared for as well.”
Even so, he can see the battle in Sam’s eyes. He feels like any delay, whether for rest or food, or even sleep, is putting his own needs before Dean’s, but Cas has to make him see it’s not like that at all.
He doesn’t want to be blunt, because he thinks there’s still a large part of Sam that believes Dean will come home whole and the man he was, but Cas doesn’t share that hope.
He knows better.
But he wins out. Sam comes to him, and lets himself be undressed, and Cas guides him down onto the blanket, and worships him, caring for each inch in and out, kissing the arch of Sam’s neck when he tilts his head back, eyes closed, whispering whatever benedictions he can still bestow into his lover’s skin.
After, held tight and safe and loved in Sam’s arms, Cas can feel him pulling himself back together.
This is a campaign, not a battle; even once they find Dean, they have to trap him, and then find a way to force Michael out, and then….
What comes next may be the hardest fight of all, but Cas knows they won’t give up.
They’re Winchesters. They don’t know how.