Fletcher Reede (Jim Carrey) is a master liar, and he even does it for a living as a lawyer. Unfortunately his lying even includes lying to his son Max time after time about coming to play with him and do things with him. When Max has had enough he makes a wish over his birthday candles that his dad would no longer be able to lie, and it works to great misfortune of Fletcher. From that time on he can't tell a single lie and he discovers that almost everything that he does includes lying, even things as simple as polite passing conversation with office co-workers. When his ex-wife Audrey (Maura Tierney) tells him that they will be moving to Boston because she has accepted her boyfriend's proposal he is unfazed at first. Fortunately for Fletcher his son's wish ends up giving him a chance to reflect on what is really important to him as all of the false things that he has developed begin to fall away. Hopefully he can change his perspective before it is too late.