This is a rare case of a book written based on a movie (Fantastic Voyage, 1966). It is also the first book by a legendary science-fiction author that I have read.
A group of scientists and a government agent are miniaturized to the size of human body cells to be injected into the body of a famous scientist (who escaped from behind the Iron Curtain) to save his life. So this is not the typical science fiction that Asimov is associated with. Rather, it is an adventure novel with thriller elements. The rescue team faces adversities encountered inside the human body in the form of white blood cells, antibodies and the fact that their ship must be navigated in a completely different environment than we are used to.
The book was written during the Cold War. Tensions and rivalry between the US and USSR left their mark in literature as well, and that theme is present here. Among the participants of the rescue expedition there is probably a spy and a saboteur. In addition to overcoming the obstacles of moving inside the body, the members of the team must also observe each other’s behavior, none of them knowing whether the other can be trusted.
I liked the portrayal of distinct characters of the main characters. Each of them has a unique set of skills and knowledge and a specific character. They are not just static and flat characters. The action of the book is carried out very dynamically. There is a lot going on, and the descriptions from inside the human body seem adequate to reality.
The book is easy to read and is a quick read. I could even classify it as an entertainment novel. This is a well-written novel with a crime plot making the reception even more positive.