As stated, however, Halo Wars’ story is not without flaws — one type specifically which banes the efforts in the Timeline and the game’s main narrative… this type flaw is, of course, a plot hole.
From a narrative standpoint, there was no practical reason for the visit to Arcadia. Although some of the missions on this world are an absolute blast, collectively they have no real place within the high-level story progression other than being a stopgap between Harvest and the shield world. The relic on Harvest leads the Covenant and humanity to Arcadia, and from there they travel to the shield world – but what is it within the arc of the story that points them from Arcadia to the shield world? Nothing is supplied during the game or in the supplemental material included alongside the game.
One might presume that after the Arbiter fled Harvest he located a second relic on Arcadia, which led his forces to the shield world and the Apex Site; but there’s no direct evidence for this. Perhaps the Covenant already knew about the shield world and their mission to Harvest, and then Arcadia, was for something entirely different? This seems just as likely due to the fact that before the UNSC even penetrated the Covenant’s shield bubble on Arcadia, the Arbiter was already on the shield world discussing his next orders with Regret. And so with a lack of proof pointing in either direction, Arcadia’s purpose immediately becomes null and strictly diversionary.
The sad part about this issue is that it could have been resolved with the addition of a few lines of dialogue from the Prophet to the Arbiter while at the Apex Site: “And you destroyed the relic at the human world? We can’t have them activating our lords’ creations at will.”
This issue with Arcadia, however, is light in weight compared to the appearance of the Flood — a concern which not only causes problems within the game itself, but also echoes outside the title’s own narrative and into the property’s overarching fiction. We know that going into Halo: Combat Evolved, the existence of the Flood is unknown to the UNSC. And ironically, in the original trilogy the Flood primarily serve as a story element, with gameplay with them typically remaining lean and redundant. With Halo Wars, however, the exact opposite is true. The Flood here were created specifically because they work well within the real-time strategy mechanic, and yet, during the course of the campaign, they have absolutely nothing to do with the story. The player battles through several levels which involve the Flood, but none of them lead anywhere fictionally and most feel like a tacked-on sidebar to the existing campaign.
Problematically, the Flood’s existence on this shield world in the first place creates a rather large hole in the story of Halo Wars. On the UNSC’s side of the story, Ensemble did a reasonable job of tying loose ends. No one knows what the fate of the Spirit of Fire was, but we can presume that, at the very least, the remainder of the crew (if they did in fact return) were detained by the Office of Naval Intelligence and their information on the Flood and on the shield world was kept under lock and key — the Timeline’s entries are sufficient in covering this ground.
But what about the Covenant?
In Halo Wars, we learn that the Covenant have known about various shield worlds for some time now, this knowledge gained during their quest for the Halo rings. Our knowledge of the shield worlds is fairly limited, but we know that they were essentially used to stave off the Flood and, when the time came, the launch of the Halo Array. In Halo: Ghosts of Onyx, the shield world is actually a Forerunner-manufactured planet which is a composite of Sentinels. Within the planet’s network of underground tunnels, a controlled slipspace rupture allows individuals to move into a micro-Dyson sphere hidden in subspace at the core of the planet. The sphere’s interior surface, similar to what can be seen in Halo Wars, is considerably larger — so large in fact, that the individuals trapped within it didn’t even realize they were in such a super-structure.
In Halo Wars, the shield world is simply a planet shell, its outer surface covered with large bodies of water and the Flood parasite, presumably having spread by way of the Covenant intrusion. After passing through this mantle-like surface and being cleansed by the Forerunner technology inside, the Spirit of Fire makes its way into the interior of the planet, which has a surface of its own — a majestic and pristine environment quite similar to that of the Halo installations. Why the Flood exist on this body at all is never explained, although one might assume that they were stored there, just as they had been on the Halo installations themselves.
The greater question, however, is why the Covenant have no knowledge of the Flood going into the events of Halo: Combat Evolved. According to Conversations from the Universe’s “Letter from Supposition” the Flood’s discovery on Installation 04 was unprecedented:
>>> LETTER TO THE COUNCIL OF DEED AND DOCTRINE >>>
Submitted humbly by your servant.
The Prophet of Supposition
The Flood: A Question of Faith
In our research for truth and answers from the Forerunner legacy, we have discovered many gifts, but never a curse. The discovery of Halo was the greatest bequest to our faith in a thousand years, but it came at a price. The atrocity committed by the Humans was devastating, but the discovery of the Flood within Halo, was perhaps as troubling.
Humans we know and understand. They are vermin to be trampled. But the Flood was unexpected. Were they placed there as a test of our faith? Are they an enemy to be conquered? Or are they an article of faith? Nature tells us to strike back when we are ourselves struck, but this event was unprecedented. Are we to rail against the wrath of the gods?
Our scientists will analyze the scraps and fragments we recovered, and as ever, we will find use for what we have learned. Perhaps this Flood could be, if not an ally, then a weapon. The Forerunners have blessed us with obscure gifts in the past. This Flood hammered the Human forces every bit as hard as our own.
We cannot assume the Flood is gone; after all, it must have sprung from some source.
The Flood, it seems, was imprisoned on Halo, but what if we calculated incorrectly? What if the Flood had sanctuary there?
I submit to your appraisal. [Conversations from the Universe]
With a hierarch and an entire ship of witnesses all being aware of this shield world location, and being at least somewhat familiar with its surface’s parasitic threat, how do the Covenant pass into the events of Halo: Combat Evolved with no knowledge of the parasite?
In The Last Voyage of the Infinite Succor, which takes place during the events of Halo: CE’s “343 Guilty Spark” level, Rtas ‘Vadumee, also known as Half-Jaw, comes face to face with the Flood, and has the following conversation with a lesser Prophet onboard the Infinite Succor:
“What is happening, Legate? What are these creatures?”
“I see you never studied, Commander. They are the Flood, one of the many tests and obstacles we must pass to activate the holy rings and begin the Great Journey.
They are mentioned in several of our religious texts. But the details are woefully inadequate given current circumstances.” [The Last Voyage of the Infinite Succor, pg. 38]
The only solution to this problem is the following: the Prophet of Regret, either alone or along with the other two Prophets, hid the knowledge of the Flood from the rest of the Covenant, much like we posited ONI must have done if the Spirit of Fire was, indeed, recovered. For the Covenant, however, this solution isn’t as easy. As revealed in The Last Voyage, the Covenant already knew about the Flood, but were unaware of their exact nature; namely, the Flood’s overwhelming voracity in consuming everything in their path. So one must wonder: why would the Prophets, after discovering these characteristics on the shield world, want to hide this knowledge from the rest of the Covenant – when they were sure to face the Flood again in their quest for Forerunner technology? As we read in The Last Voyage, more knowledge of the Flood could surely only have helped them.
There could be a thousand fixes that wouldn’t outright defy existing fiction, of course, and the problem isn’t that there won’t be one of these solutions offered in the future; it’s just that it wasn’t supplied during Halo Wars’ narrative. If you’re going to take something within Halo’s fiction to use because its gameplay mechanic would work perfectly within your title, that’s fine, just ensure that you adjust the game’s fiction to the element’s disposal rather than contradict an existing story reality without any care to patch the severed continuity.
This is another situation in which the addition of a few spoken lines could have provided a solution to this entire problem; perhaps the Prophet could have said to the Arbiter while at the Apex Site: “Oh, and Arbiter? See to it that your Sangheili warriors understand the importance of keeping the discovery of the parasite a secret. The Covenant must deal with one test of faith at time.”
Instead, the issue was ignored, and the audience is left wondering why existing fiction no longer makes sense.