The Winchester brothers investigate a series of disappearances in the town of Elwood, Indiana resembling alien abductions. They question the first victim's father, Brennan, a watchmaker who is adamant that his son will never return. Dean is apparently abducted; Sam goes to a UFO gathering to learn more about the abductions. Dean is sent back hours later and is annoyed to find Sam spending the night with a groupie from the gathering instead of searching for him. Continuing their research, Dean begins seeing a strange man only he can see and encounters a Tinkerbell-like fairy radiating an energy sphere. Dean tries to convince Sam of the bizarre events but Sam remains skeptical. Dean checks out Brennan's shop, only to find elves working inside. Sam asks Brennan for the truth and is told that he summoned a leprechaun two months ago. The leprechaun makes him a deal to have his elves build watches and save his shop and reputation, but will take his first-born in exchange. Dean is followed by the strange man and ambushes him, only to mistakenly attack another man and is arrested for assault. Sam and Brennan attempt to undo the spell but Brennan is killed by the leprechaun, who turns out to be a UFO enthusiast (Robert Picardo) seen throughout the episode. He used the faked UFO sightings as cover up for the leprechauns' activities. The leprechaun senses the lack of a soul in Sam and makes an offer to get it back for him, but Sam declines and attacks him. Finally, Sam empties a rock salt shotgun shell onto the floor which forces the leprechaun to count each grain, and reads the spell to send all of them back to where they came from. Later, Dean asks Sam why he did not take the leprechaun's deal, and Sam replies that deals are never a good thing.
Source: Wikipedia
Source: Wikipedia