"Lone Star Planet" by H. Beam Piper and John J. McGuire is a science-fiction novel first published in 1957. When diplomat Stephen Silk is banished to New Texas after writing a controversial article, he discovers a world where assassinating politicians is legal—as long as the killer proves their victim "needed killin'." His predecessor was murdered, and evidence suggests he's next. Silk must navigate deadly politics while convincing New Texans to join the Solar League against an alien threat.