C916 The Tunnel Was Opened!

Su Yi's plan was straightforward: carve a tunnel from outside the city directly to the dungeon holding Zhang Canyang. This would drastically reduce the risk of detection. Plus, escaping through the tunnel would encounter no resistance. Few would consider such a tactic, given the immense challenge of tunneling into a city. For others, it might take weeks, but for Su Yi, with his excavation prowess