From the front of the book:
You have haggled with the potter, you have given the coin to the stranger, and you have spared the life of an agent. Now, the Zhentarim is offering you a chance to join their ranks. Darkhold and the secrets of the Black Network await for those clever and ruthless enough to infiltrate the Zhentarim. A Living Forgotten Realms adventure set in the Western Heartlands for characters levels 7-10.