Book 2 in a series. Here’s book 1, Archangel Protocol.
I picked up the first book because it was 3$ and looked silly, and it turned out okay. I do love angels, though, so I went ahead and bought the second book since it was in stock.
Really, really glad I did. This book is 100% better than the first, and just stunningly good… compared to the last, but it is also quite good in general. While I was reading, I kept telling everyone about how stunned I was at the quality.