Vellen's story Report

General Summary

Previously: Wailing in the Dark
The party return victorious to Phandalin. In order not to panic the townsfolk, they keep some details of the graveyard visit to themselves, and head directly to report to Sildar Hallwinter. He listens with concern to their tale, then asks them if they wish to help interrogate the arrested girl, Vellen Firecrow, for her assault on Tharg and her links to the Talos cult in the area.
The young tiefling woman is being questioned by town guards, who quickly allow the PCs to take charge. The yipping of the five Kobold kits can be heard from the next cell. Vellen is overwhelmed and very intimidated by Tharg and their previous interactions and spills her story very quickly.
She reveals that her contact with the cult is one Backes Dunfield who was hiding in plain sight as the barkeep at Wayside Inn. His last correspondance was a magically concealed letter that said he was about to abandon that identity and join more powerful Talosians in searching for a 'relic of great power'. What might be left of Wayside after a follower of the god of destruction leaves their cover is a question that wasn't addressed. Dunfield's orders to Vellen were to kill Tharg's party, or at the very least delay their leaving town.
In terms of her arrest and punishment, it seems doubtful whether Vellen has actually taken part in the evil deeds and destructive rituals that the cult commits, and Tharg was very much not harmed in her attempted assault. It seems it's up to Sildar what to do with this relatively innocent, but potentially dangerous tiefling.
Next: A Choice of Two Enemies