The Dark Tower: The Wind Through the Keyhole is an upcoming novel by Stephen King. As part of The Dark Tower series, it will be the eighth Dark Tower novel, but, according to King, chronologically set between volumes four and five. First mentioned by King in 2009, after the series had been announced as concluded in 2004 with the publication of the seventh novel, it was announced on the author's official site on March 10, 2011. It is scheduled to be published in the spring of 2012.
The major story of Roland and his ka-tet was told, but I realized there was at least one hole in the narrative progression: what happened to Roland, Jake, Eddie, Susannah, and Oy between the time they leave the Emerald City (the end of Wizard and Glass) and the time we pick them up again, on the outskirts of Calla Bryn Sturgis (the beginning of Wolves of the Calla)?