Doing his part to help government agents, Tom Mix and his pals investigate what is happening to the whales who swim off the coast.
Visibility is at a minimum in the bay as foghorns blow. Does Tom have a handle on the mysterious shapes moving in the mist? Is that the Flying Dutchman, a ghost pirate ship? Or is it a real life pirate ship? Regardless, Tom and his crew are going after it.
The next morning, as Jane learns a little about whales, Tom hints that he might know what caused the ghostly apparition of the Flying Dutchman the previous night. The ship sets sail on the high seas, but is Tom losing his mind when he claims to want to stay out at sea to catch whoever is stealing the whales? Especially when storm clouds threaten to cause trouble.