Lake Cutscene

When Talon and Lyla get through the lake, and finally catch up to the guy they were looking for, there will have to be a series of conversations to move the plot onwards.

The first part will have them interrupted by the guards, who will attack Talon and Lyla for conspiring to keep him hidden (or something).

After that, the guy will disguise himself using his mastery of biological magic and accompany them to the resistance base in Cerin. Once there, he'll reveal that Lyla is almost certainly the real Lyla, and will reveal why he betrayed his fellow mages in the first place.

That done, they have to decide on what to do now. Kalibrand suggests they investigate the now abandoned mine, as there might be clues there... but before they can do anything, they encounter Sernt and Gaita, who tell them about the mine anyway, and they wind up heading to the thieves city instead after another conversation.