Most continue being lightweight military sci-fi books, the original three by Nylund are probably the most hard-military the books get. The major exception being the Forerunner trilogy by Greg Bear, they are fantastic books, but a lot of people call them Halo’s Dune because they are true hard sci fi books.

For the most part, the books are in trilogies, and are typically self-contained, some of the newer books, especially Kelly’s, have started pulling threads from multiple series together.

If you’re looking to pick up where you left off, Contact Harvest and Cole Protocol are the next ones in release order.