The Sorcerer's Sleep was a magical condition enabling a person to seem dead but in fact still being alive. It was used by Roger of Conté in 438 HE, when he seemingly died by the hand of Alanna of Trebond, but indeed lived on while being buried, planing his revenge on Alanna and the realm. Thus he could be brought back to live--because he wasn't really dead—by Thom of Trebond on All Hallows of 438 HE. This was the only way Thom could have brought Roger back, because no human magic could normally bring a person back from the Peaceful Realms. But it did end up costing Thom his life after a few months.