When Martin Morgan steals the Jade Box his friend John Lamar had purchased in the Orient, the latter is kidnapped by members of an Eastenn cult. When the cult members discover that Lamar no longer has the Jade Box, they vow to get Morgan. Jack Lamar, son of the missing man, has just become engaged to Morgan's daughter, Helen. A mysterious shadow appears in a room where Morgan, Helen and Jack are talking, and leaves a message that Jack's father is in the Land of the Shadow and won't return until the Jade Box is returned to the sect. The box contains a vial that holds the secret of invisibility. Jack sets out on a search for his father that ranges from the United States to the Middle East. But Morgan also stands in Jack's way, as he is determined to keep the mysterious box and use the secret of invisibility for his own needs.