Carson has rescued Duare from Vepaja and are heading back home to Korva. A great storm blows their plane into the unexplored northern hemisphere. Here they become captives of the Myposians. Myposians are fish like people that keep regular humans as slaves. They successfully escape and make their way south.
The next major obstacle is a city of strange amoeba people that reproduce by splitting in two. The two are captured and put in the museum by a drug that freezes them from the neck down. While there they find that Ero Shan, a friend from Havatoo, is also captured. One of the inhabitants falls for Duare and they use that to gain their freedom.
The third obstacle is a war in a land where the countries use giant land ships to fight their wars. After reuniting and escaping they finally make their way to Korva.
The fourth book in the Venusian series is another exciting book. It is four stories combined after Burrough’s death and are probably the best in this series. There are a lot of strange civilizations and creatures. I highly recommend this book.