How does Louis Sachar hook his readers?

Basically I THINK that Louis Sachar builds tension in the novel (story) holes by starting to make you think that the camp, camp green lake will be a camp that is green, full of life and will have a lake nearby. when really the camp is basically just like a desert, it is dry have no water of anything and no food at all. so if you had happened to go there, you would have to dig holes non stop !