When a report reaches the Town Crier office that a leopard is loose in the woods around Vanishing Lake, skepticism is the natural reaction.

Is the animal really a leopard? If so, how did it get there? If not, what kind of wild animal is it? Or is the whole thing a hoax with a mysterious purpose behind it?

Ted Wilford, working as usual for the bi-weekly newspaper during his summer vacation from college, and Nelson Morgan, the wizard with a camera, are sent to track down the truth behind this strange report. If it proves to be faked, they have the prospect of a few carefree days at the lake as the guests of the paper. If not, there could be lots of excitement and real danger as they attempt to solve the mystery.