Set moments before the start of season 4
Castiel gazed down from Heaven at the masses of humans milling around on the surface of the Earth. He briefly pondered how these beings would react if they knew what could happen if events spiralled out of control. He quickly realised contemplating this would not be productive. He needed to focus on the present, not what ifs and maybes.
He had been given an extremely important mission: to raise Dean Winchester from perdition and enlist him in the war against the forces of Hell. This mortal was to lead Heaven's army and stop the release of Lucifer from his prison. Castiel was not clear as to why this one man had been chosen but he dared not question the will of his superiors.
He did want to question why he in particular had been chosen for this difficult task of raising Dean Winchester from Hell. There were other angels who were significantly more powerful than he, but the decision of the superiors had been made. Castiel was the chosen one to crash through the gates of Hell for this one mortal man.
Now standing on the very edge of Heaven, Castiel assessed his impending journey. He knew it was imperative that Dean Winchester got out of Hell alive and he knew it was not going to be simple. As his plan formulated in his mind, he sensed his fellow soldier Uriel approach.
"Are you ready to liberate this savage from where he belongs?" Uriel snarled. Castiel regarded his friend for a moment before responding.
"I do not believe this man to be a savage."
"He is a savage, just like the rest of those creatures." Uriel nodded his head towards the humans as he made no effort to hide his disgust of their existence. Castiel looked down at them and felt as if he was beginning to comprehend why he was chosen for this undertaking.
"The decision has been made, Uriel. We must respect that decision, as we must also respect all of our Father's creations." Castiel looked at Uriel and could not help but let a hint of a smile show as Uriel pulled a disgusted expression.
"Good luck brother. I believe you will need it." Uriel gave Castiel a nod before leaving.
Castiel watched his friend walk away, believing it was his own empathy towards the human race that made him qualify for this mission. Now he hoped that he would be able to prove himself capable of completing it.
Castiel moved into position above the gateway of the underworld as his angelic brothers and sisters cleared the path. He said a small prayer before hurling himself out of the safety of Heaven and into the danger of Hell, all for Dean Winchester.
He had better be worth it.