Engaging the Enemy is book three of the Vatta series, though it's hardly the final chapter. Each of these stand pretty well by themselves, should you not be able to get your hands on all the others first, but if you like tales of pirates, space battles, the occasional bit of trading and a fair share of intrigue, you might as well just start at the beginning with Trading in Danger or one book into the series with Marque and Reprisal where things really heat up. Here the story continues as Ky gets ready to take the fight to the enemy...if she can figure out who they are.

(Source: Del Rey)