In the first episode of season four (s4e1) of TV show ‘SUPERNATURAL’, after remaining in hell for about four months, Dean comes out of a pine box. Sam has meanwhile learnt to exist without his brother. He unites again with his brother and his friend Bobby but it is still left to find out how Dean managed to get out of hell.

Sam and Dean are caught by the spirits of Meg and agent Henrickson in the second episode of season four (s4e2) of TV show ‘SUPERNATURAL’. But they also are faced with the task of saving the life of their friend, Bobby who has failed in saving some people and the dead people’s spirits are now after his life.

Dean travels back in time to the year 1973 in the third episode of season four (s4e3) of TV show ‘SUPERNATURAL’. He gets very happy to meet his father and mother as a young couple very much in love. He also has a meeting with his grandfather and hopes in his heart that his grandfather can tell anything important about their future.

In the fourth episode of season four (s4e4) of TV show ‘SUPERNATURAL’, Jack Montgomery turns into a human eater named Rugaru. The people who become infected also start eating humans. Sam wants to urge Jack to control his desires but Dean does not believe that it might be so easy to suppress one’s urges once they are developed

In the fifth episode of season four (s4e5) of TV show ‘SUPERNATURAL’, Sam and Dean while investigating some killings think that the killer is a Dracula after they notice bite marks on the victims’ body. Then the work seems to be that of a werewolf and then a mummy reveals itself as the murderer. But ie actually comes out to be a shapeshifter.

In the sixth episode of season four (s4e6) of TV show ‘SUPERNATURAL’ , Sam and Dean have to solve a case of killings in which people die of excessive fear when their hearts finally burst unable to bear the anxiety. Known as “ghost sickness”, the ghost responsible for the spread of the disease has to be found out by the brothers.

It is Halloween time and two people are killed. Sam and Dean after investigations in the seventh episode of season four (s4e7) of TV show ‘SUPERNATURAL’, find out that a witch is responsible for the murders. The witch wants to sacrifice the people as she wants to call a demon. Sam and Dean have to prevent the witch from ruining Halloween celebrations.

Sam and Dean are puzzled to find a teddy of a little girl talking and behaving like a living being in the eighth episode of season four (s4e8) of TV show ‘SUPERNATURAL’. They also find that a wishing well is actually keeping up to its name and granting people what they are wishing. The brothers have to lift the curtain to reveal the cause.

Dean and Sam search for a girl called Anna who has the special ability to hear the conversations of the angels in the ninth episode of season four (s4e9) of TV show ‘SUPERNATURAL’. This special ability of hers lures the demons and they want to abduct her. Ruby helps them in searching for her in order to save her.

In the tenth episode of season four (s4e10) of TV show ‘SUPERNATURAL’, Castiel and Uriel are searching for Anna because Anna can hear the conversations of the angels. Sam and Dean find her and they now have the task of protecting her from heaven and hell. They also want to know the origin of her special ability.

In the eleventh episode of season four (s4e11) of TV show ‘SUPERNATURAL’, Sam and Dean go on to look into a case where an abandoned house is haunted by the spirit of a young woman. A family moves into that house ignoring the dangers but Sam and Dean must convince them to leave the haunted house soon.

A strange comes up for investigation in the twelfth episode of season four (s4e12) of TV show ‘SUPERNATURAL’. While a magician is performing in his magic show and creating different types of illusions, the people who are watching the show die from watching the show. The brothers Sam and Dean must solve the mystery.

In the thirteenth episode of season four (s4e13) of TV show ‘SUPERNATURAL’, we are taken to the school where the Winchesters studied when they were young. The brothers go there because now a spirit is haunting their school. They refresh their old memories while solving the case of the school being haunted by a spirit.

Sam and Dean investigate murders in a small town and fall under the sway of the Siren responsible.

In the fifteenth episode of season four (s4e15) of TV show ‘SUPERNATURAL’, Sam and Dean investigate a town where everyone has become has become immortal. They have managed to do so by trapping the reaper. On the other hand Alastair is planning to conspire against the heaven. The brothers have a tough task at hand.

Uriel and Castiel ask Dean to torture Alastair in the same manner as Dean was tortured in hell so that he reveals information which can help in killing the murderers who want to kill angels by using Lucifer’s sword. Dean thinks he will be able to do it but Sam does not thinks so in the sixteenth episode of season four (s4e16) of TV show ‘SUPERNATURAL’.

Dean and Sam are living very normal and separate lives. Dean is a corporate man who enjoys health drinks and listens to news radio vs. rock stations. He works at a company called Sandover Bridge & Iron Company alongside Sam who is in Tech Support. It seems as if the two do not know each other. However, after co-workers start committing suicide at an alarming rate, the two find themselves working side by side to solve the murders.

Sam and Dean are shocked to discover a series of comic books titled Supernatural that accurately detail their lives as demon hunters. They track down the writer, Carver Edlund, who explains he has visions of the brothers that he then turns into comic books. Chuck reveals that Lilith is coming and she has a plan for Sam.

A 19-year-old boy named Adam calls Sam and Dean looking for John Winchester, claiming to be his son. Dean and Sam meet Adam, assuming he, 's a demon trying to lure then into a trap. However, they find out that John was indeed the boy, 's father and Adam tells them of his , normal, upbringing, which infuriates Dean.

Castiel appears to Dean in a dream and says he has something important to tell him but they need to meet somewhere private. Dean and Sam go searching for Castiel but instead find Jimmy, Castiel, 's human vessel, who has only a spotty recollection of being an angel. Jimmy wants to return to his family and normal life, but Dean and Sam are concerned about his safety.

Sam gets infected with the blood of the demon in the twenty first episode of season four (s4e21) of TV show ‘SUPERNATURAL’. He is locked in the panic room by Dean and Bobby. But they must release him as Bobby finds out that more and more seals are being broken. Dean does not listens to Bobby and the Winchesters have a fight.

The apocalypse is coming, and Sam and Dean prepare for the fight in very different ways. Sam joins Ruby on a final run to kill Lilith, while Castiel and Zachariah tell Dean it, 's time to play his part in stopping Lucifer.