is a fictional minimum-security prison located in Thunderclap
, an area of End-World in the Dark Tower
series. Several of the events of the novel The Dark Tower
occur here. A campus-like complex, Devar-Toi is also known by the names Algul Siento and Blue Heaven. The guards of Devar-Toi are a mix of can-toi
, with the management staff comprised primarily of taheen. The Devar-Toi is wardened by Pimli Prentiss
(a human) and Finli O'Tego
(a taheen). The complex houses numerous Breakers, psychics of various types employed by The Crimson King
, using their powers to attack and destroy the Beams that tie all of existence together.
Though the surrounding landscape's light quality is always dim due to a perpetual cloud-cover, Devar-Toi itself is lit by a man-made lighting device left by the Old Ones, creating a sharp contrast in mood and coloration between the prison and the outside land.
Devar-Toi and its operations are shut down permanently by Roland Deschain, Eddie Dean, Jake Chambers and Susannah Dean. Eddie suffers a fatal injury during the aftermath of the battle, and dies before the group moves on.