Jake Toren is a twinner of Jake Chambers who Susannah Dean met when she stepped through the Unfound Door near the ending of The Dark Tower. He shares the same appearance and characteristics as Jake Chambers.
Jake Toren doesn't know who Susannah is or what her, Jake Chambers and the ka-tet did, but he takes a liking to her. There is only one noticeable difference between Jake Toren and Jake Chambers: Jake Toren has Eddie Toren, the twinner of Eddie Dean, as a brother. He also has a dog named Oy, the twinner of Oy the billy-bumbler.