"Innocent at Large" by Poul Anderson and Karen Anderson is a science fiction novel likely written in the late 1950s. The story explores the cultural clash between Earth and Mars through its protagonist, a naive Martian named Peter Matheny, who travels to Earth on a mission to secure a business advisor to help Mars improve its trade relations. The book touches on themes of commerce, deception, and the struggles of a fledgling society trying to assert itself against the backdrop of a more established civilization. The narrative centers around Peter Matheny's experiences on Earth, where he quickly finds himself out of his depth. His mission is complicated by his encounter with Gus Doran, an Earthman who initially appears friendly but ultimately leads Matheny into a series of morally ambiguous situations. From being drawn into a blackmail scheme involving a jealous husband to navigating the challenges of interplanetary trade, Matheny discovers that he must rely on his wits and the dubious skills of con artists to survive and help his planet. The story combines humor with a satirical look at business practices and the nature of human interactions across different cultures, ultimately showcasing Matheny's transformation as he adapts to Earth’s cutthroat environment. (This is an automatically generated summary.)