Crawler who operates the portal cart, opening the way for the bomb-train and shutting it behind.
Zhang handled the portal aboard the repair cart during the final operation. Once The Nightmare Express had backed up, whistled twice and sped through into The Abyss, he climbed back into the cart and turned the portal off, sealing the trainyard behind the departing bomb. He was among the group Carl credited with jumping into certain death to save him.
Not described in this chapter; working from inside the repair cart.
Portal operator whose timing makes the train strike possible.
Also appears in books you've already read — spoiler-safe to their endings: