Complex sentence: Locke enters the underground station through a well but there is another flash and the well disappears and soon after Juliet and Mile's headaches go and Juliet tells the group that whatever Locke did he managed to save them.
Split into simpler sentences: Locke enters the underground station through a well but there is another flash and the well disappears. There is another big flash and Juliet and Mile's headaches go and Juliet tells the group that whatever Locke did he managed to save them.