Scalzi (Redshirts, 2012, etc.) offers his fifth in the Old Man’s War series.
The Colonial Union keeps peace among the universe’s humans, albeit one fractured after Earth’s withdrawal. Blame John Perry and Jane Sagan, Roanoke Colony leaders. Earth’s billions had provided Colonial Defense Forces troopers and outpost settlers, which allowed the Colonial Union to cope with the machinations of the Conclave, an alliance of alien (nonhuman) species. Scalzi rockets characters through assorted space adventures, with repeated appearances by Lt. Harry Wilson, CDF technician and Earth native, who finds himself wherever the action is, whether that’s in space disarming a missile trap set for the Utche, an alien species with whom the Colonial Union is negotiating, or caring for an ambassador’s dog whose survival figures into an alien civil war. Other players pop up repeatedly, including two CDF colonels, a hard-line ambassador and a female starship captain. Starships use "skip drive" to outwit Einsteinian physics and "skip drones" to communicate across light years. Human characters communicate in dialogue laced with 21st-century humor and irony, even among the CDF troopers (repurposed 75-year-old earthlings) equipped with "BrainPals," neural-computer implants. The aliens too function with socioethical and political mores replicating Machiavelli, authoritarians or third-rate dictators. Laced with oddball humor, the plot is not so esoteric that a newbie to sci-fi’s outlier world cannot follow, and the science buy in isn’t so great as to cause those who mastered introductory physics to stumble. The story simply launches human quandaries and foibles into the universe—greed, aggression, duplicity, arrogance, chauvinism and other distinctly human negatives—where they are imposed on alien circumstances, creatures and environments. Females share power and failure equally, but sex and romance take a back seat to wildcat settlements, derring-do heroes, missiles fired and messages misunderstood, all of which are offset by stunning technology, imagined landscapes and the covert destruction of Earth Station by spaceships piloted by brains-in-boxes. That makes for a gateway to the next episode.
A Heinlein-like adventure for a serious sci-fi fan.