'An amateur airman, Huntingdon ("Don") Garde, discovers a sheer-walled canyon in Central Australia. He makes a forced landing on the bank of a river which traverses the vast cavity, and while exploring the region the aeroplane disappears. Within the canyon he finds a strange community, speaking old Spanish, practising ancient torture-rites and ruled by an old despot. Garde and a girl named Liria form an attachment. After various terrifying happenings the two get separated, Liria being with the people of the canyon, and in great peril, while Garde is shut off from her by a line of sentinels and watch fires.' (Source: The Home, June 1927)