Rayna is a tentative explorer, checking out a marsh for wildlife and other useful flora and fauna. She accidentally steps into some mud and gets stuck, then begins to sink. Trying not to panic, she struggles to get free and even manages to pull herself part way out of the thick, clinging mud. But then it pulls her back in and never lets go. A sort of submergence - in that we see her sink up to her chin, then the explorer helmut gets in the way of seeing her face go under. This mud here has an undulating quality throughout the video.