It Started With a Kidnapped Pig...
The Hand of Yartar
The Hand of Yartar is the local thieves guild in the city of Yartar which is vying for a larger piece of the action, but infighting has kept the guild from having much influence.
Within the guild, a new and deadly group is flourishing, comprising ambitious young female thieves and assassins. They are masters of disguise and infiltration, impersonating officials and commoners alike in order to steal, bribe, and murder.
The Hand of Yartar might work with the Zhentarim when its convenient for both parties.