Song of Susannah (The Dark Tower, Book 6)

While Jake, Father Callahan, and Oy struggle to free Susannah Dean, whose body is possessed by a demon-mother named Mia, Roland and Eddie find themselves swept by magic to East Stoneham, Maine, in the summer of 1977, where they encounter a terrifying and dangerous worold, one inhabited by the author of a novel called 'Salem's Lot.