Fletcher Reede is a fast-talking attorney and habitual liar. When his son Max blows out the candles on his fifth birthday he has just one wish - that his dad will stop lying for 24 hours. When Max's wish comes true, Fletcher discovers that his mouth has suddenly become his biggest liability.
Madeline is married to Ernest, who was once arch-rival Helen's fiance. After recovering from a mental breakdown, Helen vows to kill Madeline and steal back Ernest. Unfortunately for everyone, the introduction of a magic potion causes things to be a great deal more complicated than a mere murder plot.