The more acute the beast's senses are, the more affinity it acquires with its surroundings, creating a strong feeling of rejection in it when it encounters unfamiliar environments. Despite not being a beast, Desmond's senses and instincts are not inferior to one. Hence he found it quite uncomfortable in the first few minutes of his underground experience.
The perpetual unevenness of the terrain, an ever-present slight incline, and a lack of natural light affected Desmond's sense of balance in a way he hadn't experienced before. Desmond overcame this awkwardness with his strong adaptability, but it didn't erase the severe expression on his face.
