The BAU is called to 1,000 square miled Angeles National Forest, California after three bodies are recovered from its Ridge Canyon Lake, a popular recreational area. The victims are all dark haired, muscular men. While those three bodies are being recovered, some boaters observing the police recovery team see their friend on shore, Nick Skirvin, being beaten and abducted by an unknown white male. Nick is later found dead alongside the forest's adjacent Lake Banter, but he doesn't fit the victim profile in that he is more slight and blonde, and the body was not found in the lake itself. When more victims are later found, the team notice that they are getting physically smaller. The team knows that the unsub is local and knows the area well, and the water burial has some significance to the ritual. After autopsies of the first four victims are conducted and some personal evidence is found on one of the latest victims, the team figures out why the unsub is killing, why there are signs of attempted revival and why the victims are getting smaller with each successive kill. Meanwhile, a distracted Rossi has to figure out what to do about the request from his first wife Carolyn, who is rapidly deteriorating from ALS.