Mass Effect Andromeda begins as a fairly slow-paced story of colonisation, but its plot soon blossoms into something far larger - a backdrop of warring races, an invasion force on a galactic scale, a missing colonisation ark broadcasting a warning signal and a giant conspiracy behind the Milky Way races even being in Andromeda at all.
These storylines take time to progress - much of Andromeda is simply about the other Milky Way races gaining a foothold - but doing so uncovers a much deeper and more intriguing set of mysteries. Exploring these threads can require hours of side-questing, and some of the details found in text-based logs or the game's labyrinthine codex can still easily be missed. So, here, I'll try and digest what we know so far of Andromeda's Remnant and Jaardan, kett, quarian ark and Initiative conspiracy plots, including the mysterious Benefactor. Much has been left tantalisingly unresolved - clearly meant as the seeds for future games, or DLC - but there are definite hints at what's to come.
In case it needs to be said, full spoilers for Mass Effect Andromeda follow.
Let's start with Andromeda's central storyline - that of the Remnant vaults which terraform worlds across the Heleus cluster and the mystery behind who made them, as well as the damaging Scourge phenomenon which caused everything to go wrong during the hundred-or-so years the Milky Way races were travelling to Andromeda in cryosleep. Andromeda's penultimate mission finally sheds some light on the Remnant creators, a race named the Jardaan, and their intentions. Not only were they terraforming the Heleus cluster using ridiculously-advanced technology - the vaults on each of the supposed garden worlds you visit - they were also working on populating Heleus with a race entirely of their own making: yep, the lovable angara are Jardaan creations, too.
The Remnant spacestation you visit in the penultimate mission, named as Khi Tasira by the kett, holds various angara designs. The Jardaan worked for a while to perfect a species with biological traits suitable to Heleus, and placed them within the cluster some 600 years ago. It's unclear, however, to what extent early angara knew of the Jardaan - as the angaran civilisation lost much of its records in the dual catastrophes of the Scourge, several hundred years before Andromeda takes place, and then the kett invasion, around 75 years before.
Why were the Jardaan so interested in terraforming the Heleus cluster and introducing the angaran race? Why did they also make the Remnant machines? It's a question the game leaves open, but there are hints. The theory I find most convincing builds upon the fact that Ryder alone, as an organic being equipped with an AI, is able to activate the Remnant vaults. This is a helpful game conceit to make your character feel special, but it may also point to the Jardaan's end goal - of leaving behind technology which can only be operated by an organic species which has achieved synthesis with an AI element. Consider the Jardaan's legacy in Heleus - one organic race, one synthetic one. And it would certainly tie into the Mass Effect franchise's frequent theme of conflict between organic and synthetic life, and the need to find a solution to it.
The Jardaan's plans were interrupted by the emergence of the Scourge, which that same penultimate mission reveals was the result of an enormous weapon detonated by a mysterious adversary. The logs where this is revealed reference the "Opposition", a group which sounds like a faction of the Jardaan themselves. It would certainly explain why, after the Scourge erupted and the entire Jardaan race left, there is no sign of this Opposition, either. The Scourge was detonated from Khi Tasira and from there spread throughout the entirety of Heleus, chasing down and destroying Remnant technology wherever it could be found. One theory posits the Opposition as a faction within the Jardaan who were against the terraforming and creation of life - either the Remnant, angara, or both. There's mention of an entity or group known as the Jheln who may have passed information of the Scourge on. Regardless, a faction against the AI Remnant seems most likely, since the Scourge-creating weapon appears to have been designed to target it.
Andromeda's final mission sees Ryder reactivate the vault network made dormant by the Scourge. The key to this goal is Meridan, a hollow, Dyson sphere-like planet - the ultimate achievement of the Jardaan - which humanity claims as its new home. With this, Heleus' garden worlds can now easily host life. This is also the final stand of the Archon, the leader of kett forces in the cluster.
While the Jardaan were native to Heleus, the kett arrived as an invading force. Dialogue with the Archon suggests the kett have invaded numerous star systems and enslaved countless races before reaching Heleus - this is just their latest expeditionary force, and the angara are only their latest prey. The bulk of the kett forces within Heleus are revealed part-way through the game to be made from converted, or "exalted", angara - again, a very Mass Effect trope, reminiscent of the Collectors' Prothean origins before they came into contact with the Reapers.
By the end of the game, with the kett's main force vanquished and the Archon slain, some kett forces still remain in Heleus - now led by the Archon's second, Primus. It's easy to see this kett force as antagonists in a future DLC, or the kett in general back as enemies in a future game set in a separate cluster. It would be interesting to see how the kett have fared in other parts of Andromeda, or, eventually, whether Ryder will take the fight to the kett homeworld. The game takes a while to really paint the kett as anything other than faceless enemies, but towards the end there are moments where they are seen as a little more. Could factions of the kett ever become allies? Primus' offer of help to defeat the Archon, a rival and your enemy, suggests it is possible.
This is, perhaps, a good time to speculate on where a future Andromeda game might be set. "Within Andromeda", yes, but with the mysteries of Heleus laid out on the table, the stage is now set for the game to go elsewhere. Any future game would undoubtedly expand on the Jaardan's influence - perhaps in other clusters, too? - or where they went after the Scourge arrived. Likewise, another game could show more of the kett empire - and perhaps make them more of a multi-faceted enemy. But it seems likely too that Heleus will not be left behind. The Mass Effect trilogy featured dozens of clusters, and while BioWare may want to keep large swathes of Andromeda clear for the franchise's future, it's hard not to see any full sequel with a multi-cluster focus. The importance of the Nexus as the Milky Way's cultural and political hub, Meridian as the new home of humanity, and the home worlds of the angara make it too valuable to leave behind completely.
There's also the matter of the quarian ark, which the game's finale reveals did make it to Andromeda in one piece - enough to broadcast a warning signal that no one should approach. It is perhaps the most obvious nod to a DLC expansion for the game than any of the other plotlines - an immediate story to pick up on, and a way to finally reintroduce not just the quarians but their shipmates the volus, hanar, drell and elcor as well. (Batarians and vorcha are not mentioned - surely they haven't been written out entirely?) The recording of the warning signal mentions an emergency on board - and again, there's a great theory as to why. The geth, the quarian-created AI race who then turned on their creators - are a huge fan-favourite part of Mass Effect. What better way to include them in Andromeda than as stowaways on the quarian ark? Their presence, once discovered upon arrival in Andromeda, would certainly count as an emergency. Having left before the events of Mass Effect 3, the quarians and geth on board would still be sworn enemies. The geth are almost certainly aware of the mission to Andromeda, since the Initiative used the geth's own data to chart the Heleus cluster's worlds. The geth were also well aware of the impending Reaper invasion - it's implied the Initiative data comes from the geth's own search for the Reapers - and so would have a good reason to want to escape the Milky Way as well.
While a threat confined to the Milky Way, the Reapers' shadow looms large over the origins of the Andromeda Initiative. Collecting SAM's memory fragments through Andromeda reveals that Ryder Sr. was one of just a couple of people within the Initiative who knew of its ulterior purpose as an escape from the impending Reaper invasion, and the fact its departure from the Milky Way was being sped along by a shadowy Benefactor to ensure it left before the Reapers descended. Initiative founder Jien Garson was the only other figure we know of to also know of the Benefactor, and it was her decision to keep it secret so as to not disrupt the Initiative's plans. Upon arrival in Heleus, Garson was murdered by an agent of the Benefactor to ensure his/her existence remained a mystery. There's scant clues as to who the murderer was, although there are a few obvious candidates for the identity of the Benefactor itself. Ryder Sr. and Garson reference someone with the ability to provide huge amounts of money and resources - which sounds an awful lot like The Illusive Man. Funding the humanity-backed Andromeda Initiative would also fit his goals - to ensure humanity prevailed even if his own plans in Mass Effect 3 did not succeed. Ryder Sr. is also shown speaking with the Shadow Broker (presumably the previous one, offed by Shepard and replaced by Liara) - another Benefactor candidate.
But the possibility remains for the Benefactor to be someone who also made the journey to Andromeda, whose identity has yet to be revealed. After all, why fund the Initiative to take advantage of the Reapers but not take advantage of it? Fans were quick to notice the surname of your squadmate Cora Harper - who shares a family name with Jack Harper, aka The Illusive Man himself. There's also the matter of Cora being mysteriously dumped by her asari squad and ending up in the Initiative at the last minute - perhaps the actions of her father. Cora may be ignorant of all of this - or BioWare could pull a narrative twist and reveal Cora as being in on these plans all along. She had been intended for Pathfinder - perhaps she had been marked for offing Ryder Sr. to ensure his knowledge of the Benefactor died with him, before that no longer became necessary. It certainly wouldn't be the first time BioWare revealed a loyal squad member as something far more.
There are many other continuing storylines, too - Ryder's mother awaiting a cure to be brought out of cryostasis, the consequences of saving (or not) the ancient angaran AI, Dr. Okeer's saved (or not) genophage research, the fact Ryder now knows the Milky Way was attacked by Reapers, and the future of the Initiative - including its first official councilor, the identity of whom you can choose at the game's end. BioWare has yet to say anything of its plans for Mass Effect Andromeda's future - right now, it has enough on its plate sorting the game's present. I can only hope we get to see BioWare's grand plan for the franchise play out - there's some huge storytelling potential here, just waiting to draw people back.