Synopsis by Janiss Garza
This Thanhouser feature offered a thrilling, if totally preposterous climax. A reporter (Harris Gordon) is sent to investigate a mysterious creature that lives in Florida's Crystal Lake and is terrorizing the nearby residents. He's not terribly concerned about the beast -- in fact, he's looking forward to the trip because he can visit his sweetheart (Barbara Gilroy), who lives there. He winds up uncovering a completely different mystery -- that his sweetheart's father had a fortune in gold bullion stolen by a gang of crooks. One of the gang takes the gold for himself, buries it, and draws a map of the location. Then he paints the map over with blue watercolor and frames it before being attacked by the rest of the crooks, none of whom can figure out how to read the painting. The reporter hears of it and takes a photo of it on the sly. Since the painting is blue, it doesn't come out on his black and white film and he discards the negative. But the dead crook's wife notices some faint lines and realizes that the map shows through. The reporter and his girl get the film back and the last remaining crook offers to take them to the island to find the gold.