Tarzan: The Lost Adventure

In Burroughs' last Tarzan story, left unfinished at the time of his death, the ape man plays guardian to an expedition seeking the lost city of Ur. In addition to Tarzan himself, his animal companions Jad-bal-ja, the golden lion, and Nkima, the little monkey, appear. Burroughs' manuscript ends before Ur is reached, but in the novel as completed by Lansdale, Ur turns out to be a society revering a giant and supposedly immortal praying mantis, which is used to slay condemned prisoners in the arena. Tarzan speculates that the creature is originally from the underground world of Pellucidar, to which Ur is connected by a system of caverns and passages. Trapped underground at the end of the story, he seeks escape by seeking out the route to Pellucidar himself.

The original Burroughs manuscript was 83 typed pages, divided into 16 untitled chapters. The manuscript ends before the treasure hunters reach the lost city of Ur. A detailed summary is posted on the Edgar Rice Burroughs Summary Project page for Tarzan: the Lost Adventure (ERB Manuscript). Of note in the manuscript is an exception to the expected racism in Burroughs' works by the inclusion of two kind African-Americans in the villains' treasure-hunting group. They defend Jean from a villain and give medical aid to her father because they are fellow Americans.

The novel received generally favorable reviews at the time of its release. In the 2005 essay "Forty More Years of Adventure" (which is included in the 2005 edition of Master of Adventure: The Worlds of Edgar Rice Burroughs by Richard A. Lupoff), Phillip R. Burger praises Lansdale's prose style in the novel as an "appropriate extension in the evolution of Burroughs' prose" (but asks "Would Burroughs have ever made Tarzan battle a 'croc'?") and welcomes Lansdale's depiction of Tarzan as the "elemental force" and the "vicious 'throw the severed head into the enemy's camp' ape-man" of the earlier Burroughs Tarzan novels.

The Lost Adventure, is the twenty-seventh book published in the Tarzan novel series. It follows the 24 main novels and two short children's novels, all by Burroughs.

Lansdale's novel was followed by several further novels by other writers authorized by Edgar Rice Burroughs, Inc.

• ERBzine.com Illustrated Bibliography entry for Edgar Rice Burroughs' Tarzan and the Lost Adventure
• Edgar Rice Burroughs Summary Project page for Tarzan: the Lost Adventure (ERB Manuscript)
• Comparison between Lansdale's completed novel and ERB's manuscript