Cloak of Shadows

The Shadow Over Faerûn
The Time of Troubles had arrived. The chaos of spilled blood, lawless strife, monsters unleashed, and avatars roaming Faerûn had come.
But wrathful and warring gods were not Faerûn's only problem.
The dreaded and insidious Shadowmasters had seized the opportunity to increase their influence and power while Mystra and her minions were otherwise engaged. The Shadowmasters had woven a mgical cloak of spells that would render the wearer invisible to their rival's magic.
The shadow over Faerûn spreads.
Ed Greenwood
Ed Greenwood is known for his role in creating the Forgotten Realms setting, part of the world-famous Dungeons and Dragons franchise. His writings have sold millions of copies worldwide, in more than a dozen languages. Greenwood resides in the Canadian province of Ontario.
Links
Ed Greenwood. Wikipedia.
Photo source: Wikimedia Commons.
The Shadow of the Avatar
Series contains 3 primary works and has 3 total works. Current series reading order on below.
Main series Forgotten Realms