As you enter the first cave, the hardness of the rocky ground makes way for soft dirt. Slowly, the rocks are replaced with mud, and slowly, your boots begin to sink. Soon, your knees, join them, then your waist, then your chest. Then, as Sigvard urges you all to watch your step, he trips himself on a root, and falls face-first into the muck. Leaving behind only a few brown bubbles, he completely disappears. Your team searches desperately, but finds nothing. You have no choice but to go on without him.
Sigvard is gone.