SPN AU: Dean Smith got transferred to FBI headquarters in Washington DC, where he meets with his new partner, Castiel Novak. After he makes Special Agent, he gets engaged to his high school sweetheart, Bela Talbot. His first case, to catch FBI’s most wanted, Sam Winchester.
The case gets personal when Sam kidnaps Dean’s sister, Jo. He goes to the motel and finds that it was too late; she had been killed. Sam Winchester didn’t flee. He sat in the corner chair, waiting for Dean to make his move. Dean charged at him, but Sam overcame him. Knocking him to the floor and punching him repeatedly until he spit out blood.
Castiel was worried about his new partner when he didn’t hear from him, so he traced Dean's phone. He rushed to the hotel to find his new partner bleeding out on the floor next to his sister.
They rushed him to the hospital, but he didn’t make it. He went to go tell his family: Ellen, Bobby, and Bela. Castiel promised them that he would find Sam and make him pay. He kept his promise. On the anniversary on his death, Castiel morns for the one who was taken too early.