The Heart of Vecna is a magical artifact that functions as a tome of ancient secrets. It gives it's user visions or audio of events in the past.
Perhaps the most dangerous effect of the Heart is the ability to link ones self with it by a mere touch, often resulting in those who come in contact going mad from the lack of control over visions and whispers.
The Heart was originally sealed away in an ancient tomb below the Frozen Sea. Rumors of it's existance have led adventurers to foolishly seek it's power for thousands of years.
It was eventually uncovered by a group of adventurers who found there demise before recovering the artifact. Only one such party member lived long enough to seek help from the nearby elves. Raaz, a tiefling prophet, had sent the adventuerers into the sea in search of it. When he learned of the parties fate and impending expidition of the elves, he recruited the aid of the nearby necromancer society to afflict the elves minds into killing one another once the tomb was clear. The necromancers then hid the heart in corpses being taken to there master so it may find it's way to the city of Vanarinis where it would then be taken to Raaz.
The necromancers were careless and one elf had escaped the tomb. Knowing of the forced betrayal and the heart the necromancers sought, he followed the trail to Vanarinis, gathering the attention of the Shadow Dragon Clan as well. The Dragons sent a young women to recover the fabled artifact for themselves.
In the city, the women and elf met along with a third in search of the heart. Aereon, another prophet, had returned to her home city to research the cults within for information on the primordials she hunted. After meeting the elf and learning of the heart, she vowed to aid him in his revenge. None knew she had planned to recover the heart for herself as it would surely contain all the information she would ever need.
The heart was found and taken by Aereon during the destruction of Vanarinis by it's elder black dragon master.