The film begins close to the end of the story, when the suspects get caught and are interrogated. Then it flashes back to three years earlier and the film proceeds forward from there interspersed with occasional bits from the interrogation.
Three years before getting caught, Bridget (Diane Keaton) lived a comfortable upper class life until her husband Don (Ted Danson) was fired from his position and sunk into debt. The paycheck for Selina, the cleaning lady, bounces again. Selina confronts Bridget and suggests she take a job as a janitor at the Federal Reserve Bank of Kansas City.
On her first day on the job, Bridget hatches a scheme to steal damaged dollar bills slated for destruction. For her team she chooses Nina (Queen Latifah), who works the dollar bill shredder, and Jackie (Katie Holmes), who takes bill carts from the Secret Service room to the shredding room. It takes some work to convince Nina to join, but Jackie joins them quickly.
The plan is that in the Secret Service room Bridget will switch a carts official Master-brand lock with a near identical lock she purchased at Home Depot. Bridget will tell Jackie the cart number and give Nina the official lock. When Jackie gets the chosen cart, she dumps some bills from the cart into a trash can before taking the cart to Nina, who then uses Bridget's key to open it and restores the official lock, and then proceeds to shred the remaining bills. Meanwhile, Bridget, in the course of her janitorial duties, retrieves the dumped bills from the trash and splits them among Nina and Jackie in the women's restroom.