Complex sentence: After a brief nap or swoon on a plateau, they get up and seemingly under a spell, three of them advance as one toward an inner recess witnessed by Edith, who cries out to them not to go.
Split into simpler sentences: After a brief nap or swoon on a plateau, they get up and seemingly under a spell, three of them advance as one toward an inner recess. They are witnessed by Edith, who cries out to them not to go.