(Yet another random normal au idea)

Sam Winchester quits law school after the tragic death of his fiance. Chasing nothing and not knowing what to do, he moves around until he meets Ruby in some city. He finds solace in her, even as she drags him into addiction and involves him in her business with the local gang, but he's too out of mind with grief to care. His addiction spirals and debt to his dealer piles up. He doesn't have the money and just doesn't care enough to worry about being killed for not paying up, so he continues to fall and accepts his fate. The last thing he expected to see when they finally did drag him away was to see his estranged older brother, but what's worse is watching helplessly as Dean makes a deal trading his own freedom for Sam's life.

Eileen Leahy is a private detective determined to find justice for her parents' death at the hands of a gang run by Azazel. Due to her own deafness, she befriends a mute man who lives in her apartment complex. Over time, Dean becomes like a brother to her, and her one refuge from the path of vengeance she's on.

When Dean is seemingly kidnapped by the same gang that killed her parents, Eileen searches tirelessly for her friend. In her search for answers, she finds out that not only does Dean's younger brother live in the city, but he also has connections to Azazel's gang. She tracks him down, finding him holed up in a run-down motel in the midsts of withdrawal. She soon realizes through his manic ramblings and frenzied explanations that Dean had been found by Azazel and threatened him to pay for his brother's debt if he didn't want Sam to die.

Dean Winchester gave up on his dreams in order to stay and take care of his dying father. Its rough work, the man had been abusive since Deans mother had died, and money was always tight with all the medical bills. Isolated for years and increasingly dissillustioned with life, he finds himself unable to speak more than the few words he is required. After John dies, he runs away to the city, unable to stay in the house where he had been hurt so much and trying to give life one last chance. Using the money he got from selling his old house, he pursues his dream and moves into an apartment complex in tbe city. There, he meets a deaf private detective who becomes like a sister to him. He's going through a rough patch, struggling with his trauma and his nearly non-existent career, when a knock comes to his door in the middle of the night. A man named Azazel is at his door. The gang leader and his goons force their way inside and inform Dean that his little brother Sam is in debt with their gang. Seeking compensation, Azazel demands the money from Dean, but bring unable to pay, Azazel offers an alternative. Dean could save his brother's life by paying with his freedom: by working at a local 'club' run by a sleezy gang member named Alistair. Dean doesn't have to think about it; Sam may have abandoned him, but Dean would still do anything to look after his little brother.

Cue Sam and Eileen taking down Azazels gang, falling in love, growing as people, and meeting friends and foes along the way (including Castiel: one of the only detectives in the police force who's not corrupt and Rowena: a member of the gang whos seeking to take them down from the inside and many more).