Almost everything about the planet defies scientific theory, including its size, lack of hydrogen, its temperature, and the presence of free oxygen in its atmosphere.

A consortium of spacefaring races, including humans, recruits Mesklinites, the centipede-like natives of the high-gravity planet Mesklin, to explore Dhrawn.

The power is supplied by self-contained fusion generators but the controls are simple pulley-and-rope systems using Mesklinite materials which the crew can repair by themselves.

As the planet warms, the complex phase transitions of water and ammonia mixtures at these low temperatures mean that a frozen lake can melt in seconds, carry the ship off in a flood, and equally suddenly leave it hung up on large rocks, unable to move as the liquid around it freezes again, trapping some of the crew below the surface in their protective suits.

Having an inkling of what Barlennan is really after, to have his people learn to fly starships and eventually explore the galaxy in their own right, Ib finally convinces the human administrators that they should treat the bug-like creatures as equals rather than hired hands.

The novel ends with the Mesklinite colonies receiving clandestine help and communication with the Hoffmans, but it is not revealed whether Barlennan's machinations remain secret from the other humans.

Even local effects, such as liberation of latent heat from mixtures undergoing freezing or condensation, can produce drastic changes in conditions.

Seemingly solid surfaces can liquefy under the pressure of the land cruisers, even as individual Mesklinites can walk on them in complete safety.

Ib Hoffman relates the story of how his son Benj, at the age of thirteen, designed and built SCUBA equipment, carefully calculating all the parameters, only to come close to dying on his first dive because he lacked a crucial piece of information about the physiology of breathing, one which all his knowledge of physics and engineering could not have predicted.