Complex sentence: Through his writings, and infamous Hollow Earth theory, the idea of a subterranean world occupied by non-human races, Siegmeister tells of his search for the safest place on Earth from radioactive fallout in order to build a paradise.
Split into simpler sentences: Through his writings, and infamous Hollow Earth theory, he told of his idea of a subterranean world occupied by non-human races. Siegmeister also tells of his search for the safest place on Earth from radioactive fallout in order to build a paradise.