The Backlash Mission Reprint edition

The second book in the Blackcollar series finds an elite fighting force at the forefront of an epic alien war once again. Denver, Earth. The twenty-fifth century. After a devastating alien invasion, the Terra Democratic Empire is occupied by the Ryqril race. The once-heroic resistance warriors known as the blackcollars now serve as strong-arm security for Denver's criminal elements. When Allen Caine completes his year-long blackcollar training on the planet Plinry, he and his elite team head to Earth to strike out against the Ryqril puppet government. But there's no way of knowing whether the remaining blackcollars in Denver will be with him, or against him. . . .