Contact by Carl Sagan

The book is a science fiction novel that explores the concept of human contact with extraterrestrial life. The protagonist, a scientist, deciphers a radio signal from a distant star system that contains plans for a complex machine. After building and entering the machine, she and her team are transported to a distant star system where they meet an alien species. The novel delves into philosophical discussions about religion, science, and the nature of human existence.

The 820th greatest book of all time