The majority (if not all) of his horror/fantasy has been collected together as well, iirc....
On "The Moon Terror": briefly, an ancient Chinese brotherhood builds on long-lost science to fulfill a prophecy reestablishing the power of China by returning the spirit of an ancient Empress who joined with a second moon the earth once had... said prophecy being fulfilled by rupturing the earth enough to recreate that second moon.
The problem with the whole thing is that it doesn't take time enough to build any sort of atmospheric convincingness at all, so it simply comes off as a contrived series of wilder and wilder stated incidents which would probably work very well on the screen, but at best form a rather hectic (even breakneck-paced) adventure yarn exemplifying all the faults of mid-range pulp at its worst (as literature). Harmless fun, mildly interesting and entertaining, but nothing more than that. However, having been curious about this one for the past 30 years, I'm not sorry to have read it....
Have now moved onto something of a different calibre entirely: the original novelette version of A. Merritt's "The Face in the Abyss"; it's been about the same amount of time (30 years) since I last read the novel, and I've never read the original version of the tale, which I understand is radically different in many ways... and so far it lives up to expectations....