The story begins when convicted bank robber Carl Quigley (Miguel Ferrer) escapes from jail. Soon after his prison break, Quigley enters a warehouse and recovers $1,000,000 he had hidden there sometime before his arrest (although it is unclear exactly how he illegally obtained the money). Quigley, with the help of two assailants, wisecracking Juice (Tone Lōc) and corrupt bank president Edward Biderman (Michael Lerner), devise a money laundering scheme where Quigley will exchange the bills from his hidden "nest egg" (these bills are consecutive and are easily traceable) for nonconsecutive bills in Biderman's bank. Biderman's money has been watermarked by the FBI because of his past in money laundering and can be identified under black light.
The film then cuts to 11 year old Preston Waters (Brian Bonsall), whose father works as an investor for a living and is very frugal with money—so much so that when he is given a blank check from his grandmother for his birthday, his dad fills it out for only $11.00. Plus, when invited to a friend's birthday party at an amusement park, he only has enough tokens to go on the kiddie rides.
After Quigley visits Biderman in his bank office to discuss his plan (along with threatening Biderman's family if he does not comply with it), Quigley explains that Juice will be stopping by Biderman's office with a check to be cashed for $1,000,000 the next day at 1:00 P.M. After the meeting, Quigley runs over Preston's bicycle while he was riding it in the bank's parking lot. Pressed for time as he sees a police car patrolling the area, Quigley gives the boy a signed blank check and tells him to give it to his dad so they can buy him a new bike. Instead, the boy writes himself a check for $1,000,000 by printing it on his Apple Macintosh Performa 600 computer. Preston goes to the bank the following day and is directed to Biderman's office by a teller (as the teller could not approve a check that size herself). Thinking that Preston is Quigley's assistant, Juice, Biderman cashes Preston's check with money from a safe hidden behind a painting.
As Preston is leaving the bank, the real Juice enters Biderman's office with another check for $1,000,000. Realizing that Biderman mistook Preston for Juice, the trio begins a frantic search for Preston. Meanwhile, Preston embarks on an extreme shopping spree over the course of 6 days, buying a castle-style house (by outbidding Quigley using the voicebox on his computer over the phone) along with many other expensive items (limousine service, go-kart track, water slide, etc.). He spends $999,675 of the original $1,000,000. Preston covers himself by saying he is making these purchases for a millionaire known only as "Macintosh" (named after Preston's computer) who lives in the castle house.
The entire time, Preston was being investigated by FBI agent Shay Stanley (working undercover as a teller at Biderman's bank and Preston's love interest) for money laundering as the bills Preston was using to make his purchases were Biderman's watermarked bills. At a birthday party Preston throws for Macintosh that forced Preston into debt (it was also Preston's birthday), he is forced into a showdown with Quigley, Juice, and Biderman. After the trio manage to capture Preston and demand to know what happened with the money, he admits Macintosh is a false name, to which Biderman suggests that Quigley can use Preston's purchases and the Macintosh name to give himself a new identity. When the trio is confronted by the FBI at Preston's castle house, Quigley claims to be Macintosh. However, with the FBI knowing that Macintosh had been using the watermarked bills, they arrest Quigley, Juice, and Biderman. After Preston gets home, his family throws him a birthday party. His father apologizes for being so harsh to him when it came to money, and his brothers congratulate him on pulling off the scheme. The movie ends with Preston looking at a picture of Shay, smiling and making a birthday wish.
- Brian Bonsall –Preston Waters
- Karen Duffy – Shay Stanley
- Miguel Ferrer – Carl Quigley
- Tone Lōc – Juice
- Michael Lerner – Edward Biderman
- James Rebhorn – Fred Waters
- Jayne Atkinson – Sandra Waters
- Michael Faustino – Ralph Waters
- Chris Demetral – Damien Waters
- Rick Ducommun – Henry
- Maxwell Strachan – Quincy Carmichael
- Debbie Allen – Yvonne
- Alex Allen Morris – Riggs