 Originally serving as public transit in the city of Lud with his partner Patricia, another monorail with female characteristics, he slowly went insane after the world went into decline and the despondent female monorail committed suicide.Roland and his ka-tet have to ride this psychopathic train in order to travel safely from Lud to Topeka so they can continue their journey toward the Dark Tower.The train seems to be connected to the children's book found by Jake, Charlie the Choo-Choo.