Once again, Planet Stories has published a great omnibus volume of Robert Silverberg’s work. The three works in this latest volume, The Planet Killers, features three of Silverberg’s short novels published as halves of ACE Doubles. The Plot Against Earth was published in 1959 (with Milton Lesser’s Recruit for Andromeda on the other side). The Planet Killers was published later in 1959 (with Poul Anderson’s We Claim These Stars! on the other side). One of Our Asteriods is Missing was published in 1964 (with A. E. Van Vogt’s The Twisted Men on the other side). Needless to say, the first two short novels are very pulpy. Silverberg was learning his craft. You’ll see a difference (and more maturity) in Silverberg’s One of Our Asteroids is Missing. A sign of things to come. If you’re a fan of Robert Silverberg, you’ll love this volume and Silverberg’s informative introduction. If you’re curious about Silverberg’s early career, The Planet Killers is the perfect place to start.