Dean's got the ghost sickness\n\n From the Season 4 episode, Yellow Fever, the above scene finds the older Winchester brother suffering from a ghost sickness which pretty much makes him terrified of everything.
However, the following episodes are all spectacular with great stories, unique storytelling, and everything that made Supernatural so great.
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1 Swan Song.
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2 Lazarus Rising. ...
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3 All Hell Breaks Loose. ...
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4 Two Minutes To Midnight. ...
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5 The Monster At The End Of This Book. ...
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6 Baby. ...
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7 The French Mistake. ...
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8 Changing Channels. ...