The BAU travels to Santa Monica, California where three bodies, burned beyond recognition, in three separate incidents, have been found at the famous pier. After the autopsies, it is learned that the victims were stabbed to death, with the burning being a cover. When a fourth victim is discovered with a slightly different mode of death, they determine that the victims were all homeless who were trying to make a living on the street. In the process of the investigation, Rossi unexpectedly runs into an old colleague among the homeless. For Rossi, finding the unsub thus becomes as much part of his regular job as it is as a means of repaying his old colleague, who refuses Rossi's help to clean up his life.