The Big Store (1941)

The Phelps Department Store is about to be sold by its new part-owner, Tommy Rogers, with the permission of Martha Phelps, the dowager co-owner. The current manager doesn't want this, as the irregularities in the books will show up. After an attempt is made on Tommy's life, Martha enlists the worst private eye in the world to protect him: Wolf J. Flywheel.