Complex sentence: Later returning to Mystic Falls in season 4 killing Elenas brother Jeremy to acquire a cure for vampirism negotiating a deal with Klaus for her freedom but, it backfires on her when Elena shoves the cure into her mouth, turning her human.
Split into simpler sentences: Later returning to Mystic Falls in season 4 killing Elenas brother Jeremy to acquire a cure for vampirism negotiating a deal with Klaus for her freedom. This however backfires on her when Elena shoves the cure into her mouth, turning her human.