On the eve of their long-delayed vacation to Lake Hoca Poca, Blondie Bumstead worries that her husband Dagwood's work as an architect at Radcliffe Construction will force him to delay their outing yet another time. Meanwhile, at the office, as Dagwood practices his tennis serve with his employer, George Radcliffe, George Whiteside, a disgruntled client, bursts into the room to express his dissatisfaction with the blueprints for his new factory. When Whiteside insists that Dagwood modify the plans by the next day, Dagwood convinces Blondie to postpone their vacation for one day. The next day, Whitehead discovers an electrical problem with the plans and threatens to cancel his contract unless it is fixed within three days. To prevent Dagwood from leaving on vacation, Ollie, another architect at the firm, decides to steal his suitcases. That evening, Ollie sneaks into the Bumstead house and is attacked by Daisy, the family dog, Ollie, his pants torn by the zealous Daisy, flees out the window with the suitcases. The next morning, Dagwood vows to find the burglar who stole his valises, and neighbor Alvin Fuddle suggests broadcasting a false report that Daisy has rabies in order to alarm the thief into revealing himself. When Dagwood arrives at the office, Ollie, who has heard the news bulletin, nervously questions him about Daisy's health. Soon after, Philpotts, a representative from the dog pound, comes to the Bumstead house to impound Daisy for observation. Afterward, Dagwood and Blondie decide to visit the imprisoned Daisy, and stop at a market to buy her some ground meat as a treat. At the market, Mona, a counterfeiter, accidentally switches purses with Blondie, giving Blondie a bag stuffed with phony bills. Upon discovering her mistake, Mona and her gang plot to steal the purse from the Bumstead house that night. When Dagwood arrives at the animal shelter, Philpotts informs him that he must obtain a written release from Daisy's victim before Daisy will be allowed to come home. After Whiteside finally accepts the amended plans, Ollie sneaks back into the Bumstead house to return the suitcases. Just as Ollie climbs in the window, Mona's gang breaks into the house. Mistaking Ollie for Blondie's husband, the thieves attack him, and the ensuing commotion awakens the entire Bumstead family and brings the police. After Blondie vouches for Ollie, the thugs explain that they were only returning Blondie's handbag. When Blondie opens the purse stuffed with counterfeit money, the police arrest the criminals. After Dagwood and the children go back to bed, Blondie spots the suitcases and the patch in Ollie's pants where Daisy bit him. Realizing that Ollie was their intruder, Blondie promises to withhold the truth from Dagwood if Ollie signs Daisy's release. The next morning, Ollie and Radcliffe deliver Daisy to the Bumstead house, and Blondie informs Radcliffe that the family plans to spend an extra week at the lake.