Veronica "Ronnie" Halifax has been a recurring character in the Winchesters' story. Dumped together with Bobby when they were little, popping up on occasional hunts—she's a constant in Sam's and Dean's lives. She's family. Until she disappears for four years, reemerging with a tortured secret and a monster on her tail. Starts pre-series, then goes forward. Dean/OC

Dean is still fighting supernatural crime with Sam when a pretty young plot twist named Sophie Gardner shows up claiming to be Dean's 15-year-old daughter. As she worms her way into his heart, he comes to realize what exactly he's been missing, and how far he'll go to fix what's broken.