Cut Off — Edward W. Robertson

In the fast-paced Breakers series, humanity faces not one apocalypse, but two: first a lethal pandemic, then a war against those who made the virus. ~ It's been six years since the plague and Tristan has spent five of them in Maui with her brother Alden. Life seems quiet. Simple. Peaceful. All these illusions are torn away when she discovers an alien installation hidden in the mountains. In response, she prepares a boat and starts work on a new home deep in the forest. But the locals don't appreciate her raiding their town for supplies. Soon, their resentment flares into open war -- and draws the attention of the aliens, who bomb the area relentlessly. With their home and lives in ruin, Tristan and Alden flee deep into the jungle of Hana. And discover a secret paradise. Yet it's not meant to last. Off the coast of China, Ness and his alien ally Sebastian are tracking an alien conspiracy. Its tendrils will lead them straight to Maui -- and pull humanity to the brink of extinction.