Each season permeated the central plot. In the first season, the brothers are looking for his father, the second found the demon who killed their mother, in the third trying to save Dean from imminent death and so on. In addition, each season brings something new to the wonderful world of the supernatural.
Viewers can only along with the characters to open all new kinds of evil. The series, starting with the ghosts, says, in the end, about vampires, werewolves, demons, and other lesser-known creatures. At the same time in the series, and is given its own version of the fight against this or that evil, largely based on real legends and myths.
Supernatural still keeps millions of fans at the expense of ordinary classically constructed series and beloved characters. The basis of the show - it's a classic road trip imposed on the investigation of abnormal incidents.