The Connors // Marching On (AU)

After watching Remedy and Supernatural I had this idea stuck in my head where David is Melissa's younger brother. They haven't seen each other for a while (he had a drug problem, but is now clean and a counseler). He gets called home after his sister starts having problems. At first she doesn't want his help, but he's not giving up. In the end they even decide to live together (and subsequently fix their relationship).