H P Lovecraft is remembered as the most influential and perhaps the greatest writer of weird fiction of the 20th century, but during his life, Lovecraft remained an impoverished writer who never had a book published and who supplemented the meager earnings from his short stories by selling his services as editor and ghost writer. Never a businessman, he didn't prosper at this either. It did, however, provide Lovecraft with an opportunity to branch out into subjects that he normally wouldn't have considered and in the 1936 Lovecraft took over a manuscript by Kenneth Sterling, which he rewrote and it was eventually published after Lovecraft's death in the October 1939 issue of Weird Tales under the tile of The Walls of Eryx. Though not the best or even the more adequate of Lovecraft's collaborations, it is notable as his single foray into interplanetary adventure fiction.
The Walls of Eryx tells of the fate of Kenton Stanfield, a prospector from Earth who is hired by a mining company to hunt for Venusian crystals that are sources of tremendous energy. Unfortunately, they are also worshiped by the primitive reptilian natives, who do not take kindly to the Earthmen's gathering them and are a constant hazard. So far, it sounds a bit like the plot of Avatar, but the natives are scarcely Cameron's noble savages and Stanfield soon learns that the natives have a sadistic streak wide enough to land an A380 on.
Lovecraft/Sterling's Venus is, in keeping with the science of the 1930s, a hot, humid jungle world teeming with all manner of life and, this being Lovecraft, none of it is scenic or beautiful and all of it is unpleasantly deadly. Stanton can only survive in the poisonous atmosphere with a chemically-charged oxygen mask and he is clad head to toe in a leather suit to protect him from the local nasties. Prospectors of the future apparently travel very light because outside of some food tablets, a knife, a "flame gun" and a crystal detector, Stanton seems rather under-equipped for a jungle expedition.
Stanton's seemingly routine outing (if ambushes and an encounter with a hallucinatory cannibal plant can be called routine) takes on a bizarre twist when he comes across an unusually large crystal clutched in the dead hand of an expired fellow prospector lying in a clearing. If this wasn't odd enough, the corpse turns out to be lying at the entrance of a 100-yard wide invisible building that fills the entire clearing. Collecting his prize, Stanton decides to explore the unseen interior of the structure, but when he attempts a few minutes later to leave its empty, twisting corridors, he discovers to his horror that the building is, in fact, a maze. Unless he can find some means of escape, Stanton faces a slow death by starvation, thirst, and suffocation–a fact that he is constantly reminded of as the body of the other Earthman starts to rot and decay in the Venusian environment. If that isn't bad enough, the natives, whom Stanton learns built the maze, gather to amuse themselves by standing at the edge of clearing to watch him die.
The Walls of Eryx is clearly a steal from Stanley G. Weinbaum's Parasite Planet that was published in Astounding Stories in February of 1935. Lovecraft/Sterling's Venus is so similar to Weinbaum's that it feels like a motion picture filmed on a set built for another production. The main character being a lone prospector tramping through the jungle with a flame pistol and canteen is too close to Weinbaum's "Ham" Hamilton to be coincidence. The trouble is, that while Lovecraft/Sterling lifted the background, they left behind the sense of place and air of adventure. They also forgot the humour, but we're talking about Lovecraft here; a man who was not exactly the P G Wodehouse of his generation.
The story also suffers because after a promising set up neither Lovecraft nor Sterling can figure out what to do with Stanton once he gets trapped in the maze. A death by slow starvation and thirst doesn't have much dramatic promise unless the character can provide some sort of revelation or emotions that make us suffer with him. For all his frustration and fear, Stanton is altogether too clinical and detached and the authors don't give his situation enough of a sense of suspense or urgency. There isn't much to Stanton and he doesn't have any inner life, so we really don't care much for him or his plight.
On the other hand, Lovecraft does manage to give The Walls of Eryx that touch of the otherworldly that sparks the imagination and raises the hairs on the back of the neck. By implying that there is far more to the natives than meets the eye, that there are more powerful and terrifying forces at work, and that the Earthmen ignore this at their peril, he gives the story a depth that sets it apart from its pulp origins.