: Do we though? There's really nothing in the story that suggests Envy is a
: separate timeline, other than the dream level coming before it. Tycho even
: references the Durandal primal pattern that you picked up at the end of
: Rage II.
In the Prologue we 100% do change to a separate timeline.
The shift from Rage 2 to Envy is more ambiguous. These would be the two Chapters that may be part of the same timeline, which I referenced in my initial post. But they also may be separate timelines as well; having a dream level in between does a lot to suggest they're separate. There's just no clear cut piece of plot that distinguishes them.
But despite that, the Prologue undoubtedly proves that Thoth is not the source of the timeline jumps (unless he can travel through time as well, an ability he never demonstrates in M2).