Nell's Tavern - Gatori, #1

On a rural roadside while relieving your morning coffee, Constable Mike Boone not expect to find a bloody human arm and a growling seven-foot tall alien. His quiet morning ride to investigate rumors of dead livestock took a grim turn. Confronted by aliens totting weapons Boone and his squad found themselves in a war, out gunned and outnumbered. His planet was supposed to be a quiet backwater world were nothing happen.
Too bad the chamber of commerce didn't tell the aliens! To them a frontier planet without a military looked like lunch. Boone realizes he is on his own if the aliens are to be repelled and enlists the aid of an old soldier banished to this world for his part in a bloody stellar conflict. Though on opposite sides two decades ago, the pair works together to build up resistance to the aliens and make a stand.
Matter are complicated by the aliens strange ally, dragons who appear to want to change sides, at a price.    As the aliens press to finish off Boone and his defenders a human fleet enters the star system bent on driving the alien invasion away. With battles in space and on the planet the action rushes to a climax.