>>539150950
IIRC, there are some notes and hints that the Absolute is basically roaming around Baldur's Gate / Sword coast and thus creating the whole refugee crisis.
Cerys in Last Light mentions that their plan was to basically avoid the cult by walking through their backyard, avoiding them by passing right by them so to speak.

How Mayrina makes it to Baldur's Gate is a mystery, maybe there is a safe route but it simply takes longer and the tieflings in their infinite wisdom decided not to take that one.
Naturally, the explanation has a multiple layers of stupid such as that Halsin would've told that their plan is utter insanity, but i guess they didn't find the route to Baldur's Gate worth sharing with him.