C251 Hidden door

"What?" Kawashima exclaimed, "You …" You mean there's a secret passage, so you can escape outside? Mr. Zu, you … How do you know? "

Therefore, the day when the mausoleum is completed is the day when all of the craftsmen die, so, there are many craftsmen who, in order to survive, will leave behind a secret passage for themselves to use when the time comes