At Tiny's bar, Dottie finds out that he needs about $8,000 for repairs. She offers to loan him the money, which she'll get as a payment from Ricky. Tiny agrees only very reluctantly after persuasion from Dottie. A man sits beside Dottie and begins coming onto her very crudely. Tiny steps in and subdues the man, taking away a gun he is carrying. Det. Farrell comes on the scene. It turns out the man is a cop, Wes Lonigan, who Farrell is there to meet. Lonigan is ready to arrest Tiny but Farrell intervenes.
Once again, the Thorsons have trouble getting payment from Ricky. Farrell suggests they go to Dante Cicollo, "bail bondsman to the stars," who is looking for women to do a job. Dottie and Brandi are impressed with his offices and his expense account. He tells them of an undercover job he has for two women. The Barsamian family, who has gotten rich in the dry-cleaning business, has been plagued by a series of arson attacks on their properties. The police suspect son Sandor, who has a history which includes some incidences of arson, but a stakeout of the family home has never been able to catch him leaving there. The job pays big bucks, but even though it is a joint effort with the LAPD fugitive detail, Cicollo admits under questioning that it is slightly illegal. Dottie is ready to turn it down, until actor Jason Alexander stops by their table to see Dante. Starstruck, Dottie takes the job. The women the find out their undercover role: maids at the Barsamian mansion.
Dottie and Brandi are put to work by the butler Frank, who is highly skeptical of their ability and qualifications. The Thorsons find many locked doors and cabinets in the home. The keys are kept by Helena Barsamian, who tries to fire the Thorson women the first time she sees them. Her husband Edouard smooths things over. Helena leaves the keys in her bedroom while she's in the bathroom. The Thorson attempt to sneak in and take them, but are interrupted by an appearance by Sandor. They observe that Helena is a shrew and that Edouard and Sandor seem to be nice guys. Husband and wife seem to have a terrible relationship, though, and Sandor seems very close to his mother.
The detective Lonigan comes back to Tiny's bar, threatening to make trouble for him and Dottie too, as holder of the liquor license. Tiny tells Dottie he thinks he's found a partner for the bar who would take over the license, but Dottie wants to keep it. That night another building burns down as Sandor watches. A night watchman also was killed. The M.O. is the same as in the other cases and the police are ready to arrest Sandor in 24 hours, even with his seemingly impervious alibi. At the Barsamian house, Brandi manages to get the keys, and she and Dottie sneak in that night while the couple is gone. The house appears empty, but they run into Sandor. He flees from them. Dottie follows him while Brandi goes to the stakeout police nearby. Sandor, covered with dirt, goes into a passageway leading to a tunnel. Dottie follows a trail of dirt and finds the tunnel. Farrell arrives at the house and Brandi takes him back inside. While they search for both Dottie and Sandor, Dottie continues her pursuit and spots Sandor entering a recreational vehicle. Inside Dottie finds the butler Frank, who is unconscious. Sandor gets the drop on her and takes away her gun. The RV is full of his arson supplies. He tells Dottie that the tunnels are part of the county sewer system that the house is built over. His father is going broke, but he insists on paying off his creditors. Sandor has been burning down their properties for the insurance money, to assure he can take care of his mother. Now he is setting up Frank to take the blame. He rigs an explosion to go off in the RV. Dottie knocks out Sandor. Brandi and Farrell arrive and they and Dottie drag out the two unconscious men just before the RV is blown to bits.
Tiny gives Dottie back her check, uncashed, saying he called in some old debts--legally, he assures her. Dottie and Brandi storm into Dante's office with a bad check he wrote them. They threaten to report his warehouses full of collateral that he hasn't reported for tax purposes, so he pays then in full. Ricky, who gave the Thorsons the information, pays off what he owes them, too. The cop Lonigan sits in front of a computer screen, where he has called up the record of Warren "Tiny" Bellows.