Elminster Enraged: Forgotten Realms: The Sage of Shadowdale, Book 3

Elminster's archenemy, the vampiric Lord Manshoon, thinks he has destroyed Elminster at last. But Elminster survives in the form of magical ash, and with the help of his scion, a fop who is growing into a true nobleman, and his longtime companion Storm, he still has a chance to counter Manshoon's insidious plots.