THE WAR AGAINST THE RULL is a novel published in 1959.
There are two main plots in the book. The first one describes the adventures of the scientist/explorer Jamieson who's the sole human aware that the animals found on the planet Carson are telepaths and that they hide this faculty, convinced that the humans will let them in peace if they stay unaware of it. Stranded on a planet with an Ezwal, one of these animals, Jamieson will have a hard time fighting him and the other giant animals living on the planet. As a baby Ezwal is brought to Earth in order to be examined, Jamieson tries to convince his hierarchy that the faculties of the Ezwal could be used by humans and that this species could be educated in order to become friendly allies.
Then comes the second main plot of the novel which describes the war between humans and the Rulls, unfriendly aliens trying to invade the galaxy. The humans are searching for a way to get rid of these intelligent worms able to borrow the appearance of the human beings. Jamieson will also be the one who'll find a solution to the Rull problem thanks to the Ezwal brought on Earth. Before that, he'll have to confront the leader of the Rulls for a terrible fight on the soil of the satellite Mira.
This report prepared by Daniel Staebler