Circlet of Lost Souls

Circlet of Lost Souls is a headgear for Shaman that increases effective caster level by one and causes their summoned spirits to have the effects of Bless. Additionally, the Circlet also provides the wearer a two point bonus to THACO that is not listed in the item description. In Baldur's Gate II: Enhanced Edition, it can be found in the Sewers of the Athkatla Slums. It is held by the Kobold Shaman who also has the Shaman's Staff needed for the quest Solve the Riddle of the Sewers.

In-game description
"Adventurers delving into a tomb centuries ago were set upon by ghosts and spectres when they entered the central crypt. The adventurers fought bravely but, one by one, they fell to the ghosts' attacks. Years later, the daughter of one of the adventurers hired a team to delve into the tomb and recover the bodies. The daughter told her group not to disturb anything but the dead adventurers they had come to collect, and the spirits of the tomb let them be. The woman kept her dead father's circlet as a memento of his bravery."