Will Trent left the fate of several main characters unclear before season 4 - so which cast members are and aren't returning to the show? Based on a book by Karin Slaughter, Will Trent follows a special agent at the Georgia Bureau of Investigation who was abandoned at birth and grew up in Atlanta's overwhelmed foster care system. Will (Ramón Rodríguez) now relies on his unique perspective while pursuing justice, which leads to the highest clearance rate in the GBI.