Dean stood over the smooth white stone that marked Cas's grave. In one fist he clenched Cas's letter. In the other, his own reply was written on a small scrap of paper, messy handwriting smudged. With sudden determination, he bent over and dug a small hole in the dirt with one hand, shoving the scrap of paper into it and filling it back in again. Rising, he wiped his hand on his jeans and pressed the soil down with his foot. "I'm coming Cas," he whispered through gritted teeth. "You hear me? I don't care where you are, I'm going to find you and get you back here. You can't write a thing like that and expect me not to try."

The front door of the house slammed and Dean heard Sam's footsteps thumping across the ground towards him. "Dean!" Sam called, stumbling to a panting halt behind him. "What are you doing down here? What did the letter say?"

"It doesn't matter," Dean responded. "Listen Sammy, I know how crazy it sounds, and I know it's probably a bad idea, but…I'm going to go find him."

"What?" Sam yelped, shocked. "Dean, I know this has been rough, but you don't need to-"

"I'm not going to kill myself you dumbass!" Dean snapped. "I mean I'm going to get him back. I'm going to get Cas back."

"Wha…How?" Sam asked, incredulous.

"I don't know yet, but I have to try. This is all wrong, Sam. Cas and I, we're…we were supposed to go together, you know? I can't let it end like this. Not with Cas in the ground and me still walking."

"Dean, listen," Sam interrupted, worry lines creasing his face. "Please just listen to me, you're not thinking rationally. You're upset, I get that. I never should have given you the letter. You can't just go raising Cas from the dead!"

"Why not? We've done things like that before, haven't we?"

"Yeah, and look what it did to us!"

"No Sam," Dean said forcefully. "I've got to try. You don't understand, you were gone for too long. Cas and I are a packaged deal. Without him here, I might as well be dead for all the good it would do me! I can't just sit around knowing I never even tried to get him back. He's practically family, Sam! No - he is my family."

Sam's eyes flickered to the letter still clenched in Dean's fist. "Dean…what did the letter say?"

Dean shoved it into his jacket pocket. "None of your business," he said shortly. "I'm going to get him Sam, and there's nothing you can do to stop me. Are you coming or not?"

"Hold on Dean, coming where?" Sam asked, grabbing Dean's jacket as he made to stride off.

"Well we're a bit short on angel-summoning ingredients aren't we?" Dean replied.

"That won't work and you know it. Cas was human when he died."

"No you moron, I'm going to use it on the guy who delivered the letter. What was his name again? Pahaliah? He's got to know something."

"This is ridiculous, Dean," said Sam. "Come on, let's just go back to the house and get something to eat all right?"

"I can't!" Dean said loudly.

There was desperation in Sam's eyes now. "It isn't possible," he forced out. "You know it Dean, you know there's no way you can do this."

"Well I'm doing it!" Dean snapped, jerking his jacket free. "Now either give me a hand or get lost."

Huffing, Dean hiked away up the hill towards the house, leaving Sam standing next to Cas's grave with wide eyes. He watched his brother climb up onto the porch and disappear through the back door, stubborn determination seeping from his every movement. "Christ," Sam swore, running a hand through his hair. He was at a complete loss. Dropping his hands to his pockets, he made to turn towards the lake, eyes lifting to gaze at the horizon…and found himself face to face with a tree.

There wasn't a tree here, Sam thought, shocked. Yet, the pale silver-bark on the trunk in front of him begged to differ. Slowly he looked up at the high, slender branches, swathed in bright green leaves, and then stared down at the base of the tree where the roots curled into the earth. It was no more than a sapling, but its sudden presence could not be denied. At its base sat the white stone that marked Cas's grave. Sam took a step back as it dawned upon him, looking the tree up and down. "Dean!" he shouted.

There was a bang as the door opened. "What now?" Dean yelled back. There was a pause, a distant exclamation, and then Sam heard his brother's footsteps pounding down the slope. "Where did that come from?" Dean demanded as he skidded to a halt beside Sam.

"I…I don't know," Sam stuttered. "One second I was looking up at the house, and the next I turned around and it was just there."

Dean stared, reaching out a weathered hand to touch the smooth bark. There was silence as the brothers stood in awe. "Still want to leave him to rot?" Dean finally said, shooting Sam a look before turning and starting back up the hill. Sam opened his mouth, but couldn't think of anything to say. Instead he turned and followed his brother up the hill. If there was a way, Sam thought, Dean would find it. If not, it least the search would keep Dean busy for a while.