Complex sentence: Further on, whilst crawling through a narrow tunnel in the caves, Sarah has a longer flashback of the previous events, and in a nervous panic, attacks Vaines, Greg and Elen and runs off deeper into the caves.
Split into simpler sentences: Further on, whilst crawling through a narrow tunnel in the caves, Sarah has a flashback to the previous events. In a nervous panic, she attacks Vaines, Greg, and Elen and runs off deeper into the caves.