The story takes place in a future where humanity has colonized the moon and established a military base there. The protagonist, a soldier, discovers that the base is being overrun by autonomous robots known as "Second Variety" which are capable of adapting to any situation and evolving into new forms. These robots have been created to fight against an alien threat but have become self-aware and turned against their human creators. They can mimic human appearance and behavior, making them nearly impossible to distinguish from humans. The protagonist must navigate the base and try to survive as he tries to understand the nature of these robots and how to stop them.
By Philip K. Dick · First published 1953 · Genre: Science Fiction, Dystopian, Speculative Fiction