From the publisher:

The legendary pulp superman battles evil in two expanded novels by Lester Dent and Harold A. Davis writing as Kenneth Robeson, incorporating never-before-published text from the original manuscripts. After Long Tom is arrested on spying charges, Doc Savage, Monk and Ham intervene in an Amazon jungle border war as they battle the mysterious Inca in Gray (in the novel that introduced Ham's pet ape, Chemistry). Then, the Man of Bronze and his Iron Crew journey to Arizona and discover a lost race and a strange mist that transforms men into stone. This pulp reprint showcases the classic pulp covers by Walter Baumhofer and Emery Clarke, all of Paul Orban's interior illustrations from the ultra-rare (and expensive!) fourth and fifth issues of Doc Savage Magazine, and historical commentary by pulp historian Will Murray, author of seven Bantam Doc Savage novels.