The Gray Assassin was an agent of the Society of the Evening Star clad entirely in gray, his face wrapped in fabric. He carried a pair of slightly curved swords with enchanted blades and hilts made from dragon teeth, equivalent to dragon's breath when used against resilient magical enemies, such as the Eternals. He was very fast and agile, had inhuman reflexes, and a fearsome reputation.
The Gray Assassin first appears at Obsidian Waste as part of an ambush to capture and beat the Knights of the Dawn to the Translocator inside the Dreamstone. Later, along with Mr. Lich, Torina Barker, Mirav, and other agents of the Society of the Evening Star, he pursues the Eternals. He personally kills Mark in Santa Monica. After the death of Civia, the last Eternal, he is killed in a duel with Bracken.
- Keys to the Demon Prison (Fablehaven #5)