Mike Axford arrives at the construction site for the Skyline Freeway with $1000 to bribe the night watchman into telling him who is behind the insurance racket being performed at the site. Before the watchman can say anything, a bulldozer starts up outside and heads toward the shack Mike and the watchman are in. Within seconds, the shack is demolished, and the watchman is dead. Mike crawls from the wreckage and is pursued by the bulldozer. He is saved by the timely arrival of the Black Beauty, which fires two rockets at the bulldozer, disabling it. The Green Hornet exits the car, picks Mike up and throws him in the back seat.
As the Black Beauty travels along, the Green Hornet questions Mike about who the racket head is. Mike tells how the watchman died before he could find out anything. The Green Hornet proposes that he and Mike work together to take the racket down. Mike refuses and the Hornet tells him to talk to his boss about it.
The next day, Britt Reid tells Mike to work with the Hornet. Mike refuses, but Britt orders him to so they can bring the racket down. Later that night, Green Hornet and Kato pick Mike up and the trio heads to Mammoth Insurance Corp., the insurers of the construction site. After a short fight, Green Hornet tells Clinton Giles to call the real head of the racket and arrange a meeting to negotiate the price for some information Axford has. The racket head, revealed to be Emmet Crown, head of the construction company building the freeway, tells the Hornet they will call Mike with the details about a meeting place.
The following evening, the criminals call the Daily Sentinel and give Mike the details. Seconds later, Green Hornet calls asking if the crooks have yet. Mike lies and says they haven't. After hanging up with the Hornet, Mike goes to leave in an attempt to bust up the racket alone. Casey tries to stop him, but fails.
Later, Crown questions Mike about the information he has. Mike says the watchman told him that Crown was in charge and he'll reveal that information unless Crown pays him off. Crown refuses and decides to permanently get rid of Mike. Before he can, the Black Beauty arrives, distracting the crooks and allowing Mike to run off. Two of Crown's men try to destroy the Beauty with bulldozers, but some well-placed Hornet Mortars take care of them. Seconds later, Green Hornet and Kato take out Crown and the rest of his men, leaving them for Mike and the police.
The next day, Mike is gloating over the successful destruction of the insurance racket and his part in it. When Britt questions him about not telling the Green Hornet, Mike claims to have planned everything in advance with the Hornet. After Mike leaves Britt's office, Casey asks Britt to let her tell Mike the secret about the Green Hornet, but Britt says no. It will only ruin Mike's fun.