Mark had never been into the underground shelters before. He only ever saw them in videos and documentaries, and whether it was through the screen of a phone or that of a computer, the scale couldn't be properly conveyed, leading to a slight shock when entering it for the first time.
The air vent should have been the first clue. It led them to a storage room the size of a football stadium. The ceiling reached above a hundred meters with a complex web of rails and cranes. On the ground, countless containers were stacked all over the place. If not for the fluorescent lights hanging above one would think they have arrived at a cramped port.
Mark once again needed assistance to get down, which added to the frustration gnawing at him. He had been told to put away his AR-15 and just watch the others work. They were going for a stealthy approach and so gunfire wasn't in the options for them.