Plot

Private detectives Gus and Dick are looking for clues in the murder case of wealthy Jonas Morton. They encounter sliding panels, a living corpse and other obstructions.

On a quiet night, wealthy millionaire Jonas Morton is strangled to death in the study of his mansion. His daughter Gladys witnesses her father's dead body and rushes to phone for help. Jonas' lawyer, Mr. Grooch, who is also present, suggest Gladys call the Wide Awake Detective Agency, run by two bumbling gumshoes, Gus Schilling and Dick Lane, whose business is on the brink of foreclosure, due to owing rent to landlord Mr. Dugan, who storms into their office demanding the money. To play a trick on Dugan, Gus and Dick draw out guns, spooking Dugan, but they jokingly tell him they are not loaded. When they throw them into a trash can, rounds begin to go off and ricochet around the room, scalping Gus and blowing off Dugan's hat, scaring him away. At the same time, Gladys arrives and informs the detectives of her father's death, as well as being suspicious that somebody is out to get his millions. At the mansion, Gus and Dick introduce themselves to Grooch, who instructs them to search for clues. The detectives do not know Grooch is actually working with a gang of crooks, the hulking Luke and femme fatale Wanda, and seemingly Jarvis the butler.

From then on, moving picture frames, lethal drinks, and a punching bookcase begin to plague the investigation. In their room, they are horrified to see Jonas' body in the closet. After being chased away by Jarvis, they run into another room to see Jonas and Gladys. Gus and Dick soon learn Jonas faked his death to see if Grooch and his gang would get his money and he offers the detectives $500,000 to apprehend the gang. Gus and Dick go to the study to see the crooks trying to break open a safe. They lure Grooch out to the hallway and knock him out, but during the melee, Dick accidentally knocks out Gus and is chased around the study by Luke. When Gus regains consciousness, he goes in to knock Luke out with a sledgehammer, but the blows have no effect. However, Luke is punched out by an boxing glove in a bookcase, which turns out to be Jonas, who warmly rewards the detectives with the money. Wanda appears, at gunpoint, telling them to give her the money, but is quickly subdued by Jarvis, who was working with Jonas, all along. As Gus and Dick happily leave with their money, they sit on the rigged chair to count it, but the chair ignites with sparks, scaring them out of the house, with the money raining all over the hallway.