The walls of the corridor leading into the tomb were covered with dozens of strange paintings depicting enslaved humans, orcs, elves, and other creatures. Each fresco appeared in the exact location described in the original D&D module. I knew that hidden in the tiled stone surface of the floor were several spring-loaded trapdoors. If you stepped on one, it snapped open and dropped you into a pit filled with poisoned iron spikes. But because the location of each hidden trapdoor was clearly marked on my map, I was able to avoid all of them.