The entrance to the fortress was like stepping into a different world. The air was colder here, biting at their skin with an unnatural chill that felt like the icy breath of a long-dead beast. The darkness within was absolute, swallowing the light of their torches and leaving only the faint glow of magical wards to guide them. The walls, made of a glossy black stone, seemed to pulse with a sinister energy, as if they were veins in the body of some ancient, sleeping creature.