Regis appears after the bout. A serious plan is called for. You tell Regis he mentioned something about drawing Dettlaff out; a method too dangerous to use thus far. After Regis explains the method is likely to be much more than simply “dangerous,” he explains there is an alternate way to reach Dettlaff: To simply agree to his demand and free Syanna. Optionally ask whether Dettlaff still believes Syanna is innocent, before asking exactly what Regis suggests you do. You’re sure that Anna Henrietta won’t agree to this. To which, Regis replies it isn’t necessary to mention it to her. Ask about guaranteeing Syanna’s safety, and where she’s being held. You reckon Damien might know where Syanna is.
However, the other plan is still a possibility; ask how you could get Dettlaff to reveal himself. Regis once again expresses an extreme reticence to this idea, before explaining one of the Unseen—an ancient and powerful vampire—has a lair nearby. As vampire society is a gerontocracy, and Toussaint is this Unseen Elder’s territory, the Unseen could summon Dettlaff without delay. Ask why the Elder hasn’t stopped Dettlaff already if you wish, then inquire how the Unseen must be convinced to help. After more of Regis’ endearing pomposity, he mentions that Madame Orianna knows where the Unseen Elder is. After more discussion, Regis asks your choice. You can:
Consider freeing Syanna, after taking to Damien.
Lean toward finding Orianna and the Unseen Elder.
Or mention you need time to think about it (which is recommended).