The fellowship that forms around Roland Deschain on his quest for the Dark Tower. Bound together by ka - the Dark Tower universe's concept of fate and destiny - the ka-tet comprises Roland, Eddie Dean, Susannah Dean, Jake Chambers, and the billy-bumbler Oy.

An order of warrior-diplomats descended from the line of Arthur Eld, trained in firearms, tactics, and diplomacy. They served as knights and peacekeepers across Mid-World before the world moved on. Roland Deschain is the last of their kind.