A straightforward disaster and recovery story based around a tourist vessel on the moon that is swallowed during an earthquake to become trapped 15 metres under the lunar dust.
There are two parallel threads to the linear storyline based around the rescue effort and on board the stricken vessel. The characters and dialogue help to make the latter aspect work. A worrying part occurs when one of the passengers reveals his UFO conspiracy theories. As a reader I thought that the man was going to be revealed as an alien and organise rescue via some ridiculous means. Fortunately this is just another plot twist and the man is simply a crank.
The true strength of this story is the science. The reader is invited almost immediately to speculate on the outcome. How will the rescue happen? An important character is Dr Lawson, a scientist on an orbiting observatory who discovers that the vessel has in fact slipped under the dust after it is initially suspected that it was crushed in an avalanche in the hills. The scientist is rewarded for this diligence by media appearances where he debunks methods of rescue suggested by the public. This is where Clarke toys with the reader and shows off his fine logical/engineering brain and it makes this a fine, fine piece of SF. When the rescue finally occurs it is quick, dramatic and matter of fact. A two page epilogue then escorts us out the door. Bang.
What works here is that the story is so tight. There is no flab. The tension is kept constantly high by events that threaten the recovery effort. A sci-fi thriller par excellence with a completely plausible plot and, rarely for Arthur C. Clarke, dialogue and characters that work.