I used to read McCollum when he was published by Del Rey, and knew that he was one of the earliest SF writers to move to ebooks and self publishing (I'm assuming he Del Rey dropped him). Now that I'm reading mainly on my Kindle, I decided to check out some of his more recent works.
This is a space operaish trilogy, with humans starting to explore the nearby stars with an FTL drive. They stumble upon a space battle and destroy the attaching ship. The victim is damaged, and only a single small, monkey like alien is left aboard. Taking him back to Earth, they discover that there is an interstellar empire, ruled by the Broa, who allow no competitors.
Book one sets the stage, and lets our heroes find out the magnitude of the problem, and who the Broa really are. Book two has the humans making a decision: do they fight and risk extermination, hide and hope they aren't discovered or submit to the Broa. Book three has the humans trying to expand their foothold into Broa space and race against time as the Broa are starting to wonder where these new aliens are coming from.
McCollum has an interesting twist, as the Broa travel via jump gates, and care nothing for the void between stars (more than once the maps of the gate system is likened to a subway map) while the humans travel FTL, but still take an appreciable time to go from star to star. This leads to some clever strategy and tactics that affect the plot.
While he is juggling a relatively large cast, his two main viewpoints characters are Mark and Lisa Rykand, both of whom are pulled into the military almost by accident (Mark's sister is killed in the first encounter and Lisa is the linguist that is first task with communicating with the initial alien survivor). Along the way, we see them becoming friends, lovers and then husband and wife.
Nothing earth shattering here, but a good read.