I wrote a jack/cas story. This one takes place in the far future, because why not? And it might be multi-chapter, the potential is there.
4173 – Far in the future, Jack Harkness is still trying to fight for what is right. Castiel comes at the right time.
teaser below the cut
Captain Jack Harkness glanced at his team. Three humans,a Cheem and a Judoon. With a gesture they moved into place and with a final signal they attacked. It took all of three seconds to realize it was a trap. “Fall back,” he yelled, trying to buy time as the demons swarmed. But the exit was blocked and while they fought desperately, Jack saw each of his team fall one by one. When the last one was dead, Jack reached into his coat and pulled out a bomb. He grinned and pressed the button as the demon fighting him tried to call for retreat. Then it went off.
When Jack woke he was in agony and alone. Squeezing his eyes shut, he tried to keep in the screams. It wouldn’t do any good anyway. Suddenly there were faint footsteps among the corpses. He forced his eyes open and looked up into deep blue eyes.