Yalah Gralhund
A human matriarch of a longstanding Waterdhavian family who is deeply ensconsed in the leadership of the Zhentarim. Her late husband was a member of the leadership of the criminal network. After his death, Yalah sought the help of a newly arrived dark wizard to return her husband to life. In exchange, she would use the Zhentarim and her family wealth to complete jobs and tasks for the dark wizard, which allowed the wizard, Manshoon, to become the de facto leader of the Zhentarim and split them into two warring factions, though the majority of the network is now loyal to Manshoon.
Manshoon did bring her husband back to life, but he returned changed; simpler, kinder. Yalah was outraged but the Wizard, having done what they agreed and gained control of the majority of the Zhentarim, blew her off, refusing to do anything else for her. Yalah discovered that Manshoon wanted the Stone of Golorr and worked to steal it for herself before he could, planning to barter it for her husband’s return, but the Doomtaker’s agents kidnapped him before she could offer the deal to Manshoon.
Yalah agreed to give the Stone to the party in exchange for a portion of the funds they find in the Vault and a magical, non-doomsday device of her choice. In exchange, she offered you the location of the Zhentarim’s primary hiding place (The Hideous Maiden in the Dock Ward and agreed to assist in the fight against the dragon vault guardian.