The first volume in the Chronicles of the Lensmen, Triplanetary brings a tedious 6-chapter introduction to the universe of the Lensmen before focusing on the intricacies of the story itself… the story of a time before the Lens, and humanity’s first successful encounters with the agents of Eddore. There’s a lot of science, a lot of heroic secret-agent-scientists, and a lot of interstellar conflict with impressive technobabble. Clearly, this is where space opera was born.