These two were my last purchases.
Both of these books are set after the Human - Covenant War but are interesting as they show something not usually explored and asked in Military Sci-Fi works. "What happens when the war's over?" The answer in these books for the Halo Universe is simple. Despite the hand shaking of Halo 3 and declarations of Peace no one has been able to forgive one another with Humans rightly mad that they were put on the verge of extinction and the races of the Covenant angry that all order has collapsed within the Covenant. So these books pretty much explore people of both sides attempting to continue the conflict through Black Ops and dirty dealings whilst others simply try to survive and maintain the peace.
Also some shit with the remaining Spartans forms a good amount of the plot but to be honest I find the average revenge hungry Human soldiers/Noble Elites out to restore their greatness side of the story to be more interesting as it reminds us that Wars, especially the aftermath, are not pretty nor is everything going to be better just because the actual fighting has ended.