Of Glocca Morra, Ireland, Finian McLongeran, who has his own unique belief system of Irish legends, uproots himself and his adult daughter, Sharon McLonergan, and heads for the mythical land of Rainbow Valley, Missitucky, USA where he believes he will become rich. One of those beliefs is that burying a crock of gold in Rainbow Valley will make it multiply, due to the power of rainbows and the Valley's close proximity to Fort Knox. Finian considers that he "borrowed" the crock of gold he has from the leprechauns of Glocca Morra, which he plans to return once he makes his fortune. Little does he know that in taking the gold, the leprechauns can no longer make wishes come true and are slowly turning mortal. One of those leprechauns, Og, has come to retrieve the crock of gold to save himself and his fellow leprechauns. Finian and Sharon's arrival in Rainbow Valley coincides with the return of the Valley's prodigal son, Woody Mahoney, who has come to repay back taxes before his land is ...