Let's add a friendly image so that people don't see any spoilers by accident.
So, the way I see it the Emperor probably tailed Shadowheart's team who liberated the Astral Prism. Maybe he even got the Nautiloid and some cultists and Mindflayers from the Elder Brain so that he could extract Shadowheart's team. Orin left her sibling on there for good measure. Mindflayers doing Mindflayer things they abducted Shadowheart.
But as soon as the Prism was close enough the Elder Brain lost its grip on the Emperor. Probably just him because he already was able to leave an Elder Brain once. Seeing the opportunity he killed the Mindflayers near him and took control of the Nautiloid.
Being the practical Mindflayer he probably sought to build an army of tadpoled people with super duper Illithid powers to fight the Absolute. He went to Baldur's Gate to find more people and thus snatched up Tav and the others.
The Githyanki were in close pursuit and disrupted him so he had to flee. When the Nautiloid arrived on Avernus he hid inside the prism.
I'm not quite sure where Lae'zel fits into all this. She probably went aboard the Nautiloid to get her Mindflayer head but was captured instead. She didn't know anything about the Prism because it was way above her paygrade.
What do you think happened? Or is there an official version of the events that lead up to the game?
Orin's sibling was the first of the Absolute's tadpole victims, weren't they? Haven't played in a couple months but that's what I remember from the dark urge storyline.
I was also under the impression that the emperor was in the astral prism since before the story started. I'm not sure if the mindflayers knew about the emperor either since they just left the artifact in a bag on the ground - their mission seemed to be all about tadpoling people
The story was left open to interpretation but I'm inclined to think the emperor was not involved in any kidnapping or tadpoling.
And Lae'zel was definirely part of a mission to recover the artifact (for Orpheus - they definitely don't know about the emperor) and got captured, she wasn't just hunting mindflayers
Fuck I've got to finish this game before I read this post... I am 10 hours in and it feels like I've hardly started.
You have! So much left to do lol