The Relic is an item obtained in The Temple at Senntisten. It is the relic from the quest Devious Minds that was stolen from Entrana by the assassin. The player receives the relic back from the assassin to give to Azzanadra during The Temple at Senntisten. If the player tries to take the relic to the High priest on Entrana instead of taking it to Azzanadra, the High priest yells "Look out, he's got a boulder!" The player is then knocked out and wakes up on a boat at the Port Sarim docks.
After The Temple at Senntisten, Azzanadra will tell you that the relic is a catalyst for holy power and is pretty useless by itself. He says that it causes the Barrows icon to give off a larger amount of holy energy, which is then amplified using Frostenhorn to be able to communicate with Zaros. He also says that because the Saradominists have carved their symbol on it that he would want to be far away from Saradominist lands once Zaros sees it.