"These tunnels were first dug out during the Es war, as a means to hide innocent Marked during that time. Unfortunately, it was very unsuccessful. The only thing they managed to save was equipment and their history."
He turns left at a split in the path, making sure that you were all accounted for.
"This tunnel network is all over the planet. Despite its large size, it's only known by the people who tried hard enough to find it. It's mostly knowledge hidden by people high in command, so they can evacuate certain individuals safely."
You come to a stop to a wooden door, braced with rusty metal.
"Doors like these are all over the place, only able to be opened by the Marked. So of course, these are the most well preserved."