This is an old-time SF book in the sense it's a story about humans having a number of bases or towns on a few planets and moons in the solar system connected by rocket ships. Certainly, most of the action takes place on Earth's Moon. It's also a sign the book was written nearly 50 years ago that it envisions a productive city of 50,000 on the Moon by the year 2040.
The book was published in 1961, so if there are some inaccurate descriptions of the Moon's geology, one should make allowances since humans had not yet sent probes to the Moon. The premise is that the Moon has a region in which there is a "sea" of dust tens of meters deep. This is a peculiar sort of dust that flows almost like a liquid. It also assumes the Moon still has geological activity that could cause a large venting of gas. The plot has a tourist craft "sailing" on this sea of dust when the gas vents. This causes the craft to fall into a temporary pit in the dust, after which the dust fills in over the craft leaving it buried.
The craft is unable to get itself out of this buried state and the dust interferes with radio transmissions - leaving them out of contact with the rest of the world. At least in theory, the craft has enough air to keep everyone alive for a week.
There is a standard procedure that the craft reports its location every hour by radio. When the hourly reports cease, the authorities are alerted that something is wrong. Based on knowing the general route of craft and the time of disappearance within an hour, a very general idea of its location can be deduced. Although the authorities are aware of a tremor occurring around that time, nothing is known of the gas venting. Nor is there any other reason to expect the craft is below the surface.
What follows are efforts by scientists and engineers to locate and rescue the craft using very limited information and resources. While the rescuers close in on the location and how to get the people out, a series of complications arise that must be dealt with as well.
While the characterizations are not that deep, there are a number of individuals who contribute additional elements to the story.
The book is a classic for good reason.