- As the planet Reach falls to the alien alliance known as the Covenant, a lone human ship—the UNSC Pillar of Autumn—fled into slipspace and has arrived at a place that could change the course of this decades-long war. An ancient, mysterious ringworld: Halo.
With human forces scattered across the surface of this immense alien construct, Staff Sergeant Marvin Mobuto must now lead his fellow crewmates—survivors from the ship’s brig—back to the Autumn’s crash site to rally and regroup with their allies. Desertion, drunk and disorderly, and murder are only a few of the charges that Mobuto's squad carries—and keeping them in line might prove to be just as difficult as surviving the zealous, entrenched Covenant warriors who believe they have found the gateway to paradise.
But as war rages across the ring's landscape for control of the installation’s weapons and secrets, a far more terrible threat from deep within Halo’s underworld is hellishly unleashed that transforms this conflict into a desperate battle of survival for UNSC and Covenant alike....
via: https://www.halowaypoint.com/news/canon-fodder-parasites-cake
If Mobuto sounds familiar, it is because he was the first UNSC human reclaimer found by 343 GS in the book Halo: The Flood. Master Chief finds his body deep in the library and is impressed by how far a normal marine was able to make it against the flood. This should be good.
I was about to comment that this feels like a companion piece to The Flood. I wonder if or how much it will weave in elements like Silva's sideplot and the existence even of Wellsley.
The Flood, being a very early piece of Halo side content, has a lot of elements that aren't exactly non-canonical, but do have a little bit of "early installment weirdness" compared to how the tone and setting developed.