Complex sentence: Holloway swings out to investigate, using a rope made from their clothes, but nearly falls when the Cube suddenly shakes; she climbs up and grabs Quentin's arm, but he drops her to her death, telling the others that she slipped.
Split into simpler sentences: Holloway swings out to investigate, using a rope made from their clothes, but nearly falls when the Cube suddenly shakes. She climbs up and grabs Quentin's arm but he drops her to her death, telling the others that she slipped.