Mook was a Shadow Thief who operated in Athkatla.

If you sided with Bodhi in Chapter 3, you will have to go the Athkatla Docks, kill Mook, and retrieve the Smuggled Shipment off her body. If you sided with Aran Linvail, he will ask you to meet Mook in the Docks. When you have talked to Mook Lassal will appear and kill her. You will then have to fight off Lassal and report back to the Shadowmaster.