Gildersleeves has had 2 recurring habits lately, one is his lovely neighbor and sister of his rival Bullard, and the other is his interest in detective work. He drives Ellen Knickerbocker out to the house he just investigated, and conveniently runs out of gas on the lonely road. She pokes fun of his little trick, and his detective hobby.
To impress her, he agrees to quit playing detective, then the next morning, he lets Leroy take possession of his mail order detective kit. Not only Leroy, but the whole family is happy over the decision, and Leroy excitedly rushes out to put it to good use. Birdie is especially relieved because detectives are always getting into trouble on the radio shows.
Leroy races in to report that Ellen has had her valuables stolen, and to help her out, Detective Gildy comes out of retirement.
When Bullard returns home, he’s not happy that his sister turned to Gildersleeves. Will Gildy prove that he has a handle on the thieves? He plans a trap to lure the burglars in, but Bullard isn’t happy to be putting himself in danger. Leroy is all too willing to go on the real life adventure, but wisely, Gildy goes it alone.
Though he hides out to keep an eye on his trap, it seems that everybody can find him. Gildy stakes out the Bullard home. Suddenly there are suspicious footsteps in the night, a loud crash, and Gildy falls out of his tree stand to nab… the professional detective that Bullard hired. .