Sam
Sam woke up to the low hum of the air-conditioner. Yellow light from street lamps made its way through the curtain into the motel room. Apparently, his blanket was too scratchy for his unconscious body as the cloth was no wear to be found on the bed, leaving Sam shivered.
He groaned, refused to open his eyes, right hand reaching down his bedside, searching for the lost blanket. Nowhere to be found on the right side. He gathered his half-awaken strength again to roll on his left. He reached down again. His finger found something soft. Sam figured it was his blanket so, naturally, he pulled it up to cover his body. Now he could drift back to his peaceful sleep on this quiet night. Hmmm… quiet? Too quiet. There was no sound of his brother breathing.
Sam opened his eye and got up in the instant. The bed next to his was messy but vacant. He jumped off the bed quickly. Dean had just returned from Purgatory. Maybe his brother might have a secret or two but Sam wouldn't take a chance. Carefully, he twisted the doorknob and soundlessly pulled to open to the outside where the Impala was parked. The car was gone.
Dean
Dean knew he had escaped Purgatory, but his subconsciousness was still trapped somewhere in that cruel realm. His dream reminded him of the endless night filled with blood and gores. This night was not an exception. In his dream, Dean prayed he would wake up soon, and he opened his eyes to the dark motel room with a damp smell of mold hitting his nose.
Better than those freaking woods. Dean thought. He looked at his brother who was sleeping peacefully on the next bed. Even with no light, Dean could still see Sam's chest rose and fell in a serene rhythm. Dean got out of bed, grabbed his red leather jacket along with the impala's key, and went outside in his t-shirt and sweatpants. Dean knew he would not be able to sleep tonight or any night. Not like this.
Castiel
After Castiel and Dean had escaped Purgatory, the angel spent most of the time answering prayers around the world. He took it as his mission to make the world a better place. This morning, he had saved the boy dying from plague in a civil war, and conjured water to save a village in Africa. He was not content. It didn't lift the weight of his own sin from his shoulder. Yet, everyday, he would answer to one particular prayer, and flew right away to Dean Winchester.
Sam
It wasn't the first time Dean's missing from his bed along with the impala. This time, Sam had his cellphone's GPS turned on and left it in the car. Sam trusted Dean with his life and more, but he couldn't help trailing with all the curiosity building up in his chest. Sam turned on his laptop, tapped his finger on the desk because it took so long to boot. When it was ready, Sam only needed a few clicks to locate the impala. Since he didn't have a car, he memorized the location in his head, ran out of the room, jump-started the nearest motorcycle he could find, and headed to the destination.
Castiel
The hood of the impala was cold against the thin fabric of his mental patient pj, and the wind was breezy enough to send a shiver down a man's spine, but the angel Castiel sat still like a marble statue when Sam Winchester found him. Good thing Sam had the motorcycle turned the other way so the headlight did not shine on him. Disturbing light was the last thing he needed at that moment. Sam parked the bike and walked toward him in confusion. "Cas, what the…" Sam tried to ask but never finished because Castiel interrupted him first. "Shhh…" The angel hushed. "Your brother is resting."
In Castiel's lap, Dean was sleeping soundly, using his friend as a pillow, and the trench coat as his blanket. Dean had found his place, a home to return to every night, in the warmth and comfort of the angel of Thursday.