History of Shadowdale - Shaerl and Mourngrym Meet and Marry
The implications of Khelben "Blackstaff" Arunsun "choosing" the last two lords of Shadowdale (Doust Sulwood and Mourngrym Amcathra) were not lost on the Dale's powerful neighbor to the south, Cormyr. An agent was sent northward to divine Mourngrym's true intentions and to guarantee the Dale's continued good relationship with the throne of the Purple Dragon.
The agent was a rogue named Shaerl Rowanmantle, sent by Vangerdahast (though all paperwork on this matter has been curiously incinerated in Suzail, so all is hearsay and tale). Shaerl discovered more than she intended and fell in love with young Mourngrym. The two married and became the lord and lady of Shadowdale. Shaerl's loyalty is now to her husband and to the land they co-rule. This was probably not the intention of the Cormyreans.