Synopsis: Main Character: SpecOps Commander Rtas' Vadumee (aka: Half-Jaw)
Takes place - Halo: Combat Evolved Level, beginning of Chapter 6: 343 Guilty Spark, and later, on board the eponymous ship.
Supreme Commander of the Fleet of Paticular Justice is the Arbiter from Halo 2
It is revealed how Rtas' Vadumee (Half-Jaw) lost part of his jaw, it was sliced off by a close friend that was infected by the flood
It shows that other non-sentient life forms could also been infected by The Flood, such as those in the Hunting Preserve on the Infinite Succor.
The Legate tells Rtas' Vadumee that The Flood are mentioned in the Religion Text as one of the test before the Great Journey.
It is the first time we see a duel sword wielding elite, we also see an Elite with an equiped shield
It shows that knowledge of an indivdual can be used by any other Flood, like a collective mind. When Rtas' Vadumee teammates were infected and assimilated, the Flood could open any door and access any system on the ship right after the teammates were assimilated. Near the end of the story, Rtas is confronted by a Flood "brain form" entity on the monitor, which bears a resemblance to the Legate that was on board. Whether the Prophet in question was or wasn't consumed by the Flood is unconfirmed.
Takes place - near the beginning of the game Halo 2
This is the testing of Master Chief's Mjolnir Mark VI Armor.
Maria is a retired Spartan, and has settled down and had a family. Spartans do have "some legal recourse" about the matter of retiring, as stated in the Conversations from the Universe booklet, thought it also states that, as of two years prior to Halo, no such retirement has been pursued. Her children are likely to have excellent physical properties just like their mother, but without the augmentations, they could reveal the Spartan program to the public. It is possible that her children could be recruited into the Spartan-III Project. Also, the idea that she retired may just be a cover.
This story shows a low Earth orbital skydive
A spartan with the new Mjolnir armor can jump into the second floor of a building.
It shows how the last bridge, to reach the exit of the installation in the game was disabled
The six Flood combat forms that Johnson kills, it is unclear whether one of them was Jenkins (if they unlocked or found away around the door that Johnson locked), this would mean the book, Halo: The Flood with Jenkins side story contradicts it. But it also supports why Jenkins could control himself at times through-out the book.