Tarzan and the Madman

Tarzan and the Madman was published in 1964, fourteen years after Burroughs's death, having been written sometime in the 1940s but never sent to a publisher during his lifetime. The novel returns to the African jungle setting. A series of attacks across multiple villages are being conducted by someone calling himself Tarzan, evidently a deranged man who genuinely believes himself to be the ape-man.

The real Tarzan investigates and discovers that the impostor is Colin Randolph, an aristocratic Englishman driven mad by a head injury and a tropical fever. Randolph is being manipulated by a small criminal organization that has been using his Tarzan delusion to commit crimes the locals will blame on the actual Tarzan. The doppelganger plot is familiar by this point in the series, since Burroughs had used it more than once. The novel ends inconclusively because Burroughs had not given the manuscript final polish before his death. Of interest mostly to completists working through the full Burroughs Tarzan canon.