Release Message:  A direct sequel to The Land That Time Forgot , continuing the lost world adventure of Bowen J. Tyler trapped in a biological system of prehistoric creatures. Written by Edgar Rice Burroughs.

Description:  The novel begins with the organization of an expedition to rescue Bowen J. Tyler, Lys La Rue, and the other castaways marooned on the large Antarctic island of Caprona, whose tropical interior, known to its inhabitants as Caspak, is home to prehistoric fauna of all eras.