This film essentially begins with a young woman by the name of "Betty Marsh" (Mary Russell) coming out West in search of her father who has gone missing while searching for an ancient city rumored to have vast sums of gold. As luck would have it, while riding in that area, the Three Mesquiteers come upon an elderly man who was with Betty's father and just happens to have a book which contains directions to the lost city. Unfortunately, not long after regaining consciousness, the man is murdered and, as a result, the Three Mesquiteers, along with Betty and her companions, set off to find the lost city and rescue Betty's father. To get there, however, they not only have to travel through an extremely hostile territory, but they also have to contend with a murderer within their group who is willing to do whatever is necessary to have the gold all for himself. Now, rather than reveal any more, I will just say that, not counting three other films from other various studios, this was the 4th film in the Three Mesquiteers series produced by Republic Pictures. In that regard, like all of its predecessors, this movie has a rather short running time (approximately 58 minutes) as well. Admittedly, the acting is rather basic but, even so, the supernatural element adds a bit of suspense not normally found in any of the others (except possibly, "Ghost Town Gold") and, for that reason, I have rated the film accordingly. Average.