Dean watched Cas disappear in despair as he looked around at the crazy maze of black, macabre trees that surrounded him. And he knew. He knew just from the feeling at the pit of his stomach where he was: Purgatory.

Dean turned all the way round on the spot as the crowded, taunting, spindly trees continued on and on. A flutter amidst the trees every few seconds kept Dean's instincts razor-sharp, especially now Cas was gone. Cas. Where the hell had he disappeared to? And was he back to normal again, before he'd taken on the burden of Sam's insanity? From the couple of seconds they'd interacted a moment ago, the unsure voice that was tinted with crazy seemed to be absent, and replaced again with the husky voice that Dean would welcome back so warmly.

As if the thought of him had called his angel back to him, Dean was startled by the familiar flutter of wings behind him as he turned around to see Castiel.

"Where the hell did you go, are you crazy?"

Cas looked at him and smirked in a way that Dean had missed.

"Okay, wrong expression. Sorry."

Cas started to talk regardless of Dean's conversational blunder.

"I searched around. I've looked at most depths of Purgatory I can access in the last two minutes and I cannot find your brother anywhere."

"Wait, there's places you in here you can't access?"

Cas nodded. "There are some things in this place that even I would be no match for, Dean. I daren't go further."

That made Dean nervous, but at least now Cas was with him once again. He didn't know why, but when he was with him, Dean could never be totally afraid. Castiel brought with him a sense of protection, of security, that no one else – not even Sam – could.

"Cas, we're, um –"

"We're trapped here until Sam, or anyone else up there, figures out how to get us out."

Dean suddenly remembered Crowley and how the Winchesters had once again been outwitted by a demon. ...If he even was one. "That son of a bitch."

Dean wandered over to one of the skeletal trees closest to them and leant against it as he slid down to the floor, feeling exhausted and overwhelmed. Where was Sam? How were they going to get out of this one? How many more hits could they take?

Cas approached Dean at the bottom of the tree and slowly joined him in sitting on the forest floor, which was freezing cold. He looked sideways at Dean, who was looking down in sore defeat.

"Dean. It's okay – I'll protect you here."

Dean looked up and was immediately caught off guard by Castiel's sapphire blue eyes searching deeply into his own. It seemed odd, something so beautiful in a place that was so gloomy and dark. Dean had never felt more thankful to have his angel here with him, in this...nothing.

"I know you will."

Dean leaned over and reached his hand over to hold up Cas' chin as he kissed the angel's dry lips tenderly. He ran his hand over his stubble and kissed again as Cas accepted what Dean was doing and returned the kisses. Dean moved his hand to the back of Cas' head as he ruffled his hair playfully, until Cas got up so that he was kneeling over on top of Dean at the base of the tree.

Cas held the shoulder where he'd once left his mark on the hunter and ran a hand through Dean's hair with the other as their tongues continued to dance together. Dean placed his hands firmly on Castiel's hips and made his groin as close to Cas' as possible. He let out the occasional moan between kisses as Cas sent an electrifying spark between the two of them.

"Dean –"

Cas tried to speak between breaths as the kisses became more and more eager and impatient.

Dean withdrew for a second and looked into Cas' eyes. They were so blue that they felt like an ocean that Dean could drown in.

"You make me feel safe, Cas."

Cas relaxed his body a little and ran his hand gently down Dean's cheekbone.

"We will get out of here Dean. I promise."

Dean nodded and then resumed kissing passionately as he felt Castiel's body tighten on top of him. Dean felt himself get an erection as a strong pulse in his groin increased and Cas' kisses moved down to Dean's neck affectionately. The angel felt Dean's pure pleasure at what was happening and Cas felt himself give in to the desires he was having.

Even in the depths of Purgatory, when it seemed they were screwed, when hope was hard to find, Cas was there for him. Always.