"How about digging a tunnel?" the field agent suggested again.
"The steel-structured outer wall goes fourteen meters underground, and we don't have suitable digging tools... How many hours do you plan to dig?" Ding Chao replied helplessly.
Just as everyone was at a loss, Yin Xiang looked up and saw a vent covered with wire mesh, high above the ground, more than twenty meters up. Inside the vent, a few dirty propeller blades were slowly turning.
"A vent!" Yin Xiang said, "We can crawl in through the vent!"
"A vent..." Ding Chao fell into thought.
Though the production workshop of Plant No. 105 is completely sealed, the personnel restrooms and offices inside the building are connected to the outside via vents. But Ding Chao clearly remembered the design blueprints stating that all the interior ventilation ducts were of a 400mm by 550mm specification. A normal human could not fit through... unless the person was an acrobat skilled in the 'Bone Shrinking Skill.'
