A 14-episode serial in which Mala, a Polynesian in the employ of U.S. Intelligence investigates sabotage on Clipper Island. A gang of spies causes the eruption of a volcano, for which our hero is blamed. He convinces the local Princess Melani of his innocence and helps her ward off a takeover by rival high priest Porotu.
The Eagle uses sky writing to make threats against a corporation. Nathan Gregory owns a traveling fairground and is thought to be the Eagle. Craig McCoy is a pilot who goes looking for the Eagle when Gregory turns up missing.
A mysterious criminal known as The Whispering Shadow commits crimes by means of a gang he controls by television and radio rays. Jack Norton, whose brother was murdered by The Whispering Shadow, suspects that the eerie Professor Strang - whose ghostly wax museum contains figures far too lifelike - may be involved in the crimes.
Filmed in the Sierra Nevada mountains near Sonora, California, this Universal serial is Universal's 40th sound-era serial. Eagle Scout Bruce Scott, leader of Martinsville Troop Number One, and his pack sets off in search of lost treasure and finds adventure.