Olra, the Shadar-Kai, is the gatekeeper for the portal to the Shadowfell. She works for Tiamat, kind of, but her job is to make sure that Trine is free and clear of Drow and Light Speakers.
Other than that main purpose she enjoys making Rumpelstiltskin-like agreements with passersby. The group thought about attacking her, but opted to make a deal with her. The heroes each gave her a prize for knowledge of their “greatest desire.”
After that, she allowed us to go through the portal, and trapped us on the other side. She kept a Shadow Il-Kash behind to keep tabs on the group.