The second book in the Sten series is “The Wolf Worlds,” written by Chris Bunch. Growing up on Vulcan, a manufacturing plant, Sten gains knowledge about the survival of the hardest-bitten. The entire galaxy’s Eternal Emperor possesses massive forces, but to appease the Wolf Worlds—a tiny group of planets that have elevated space piracy to a low art—he turns to Sten and his Mantis Team of militant problem solvers. The book presents a grim, gritty future full of space warfare, unusual worlds, and massive explosions.