Complex sentence: A hundred years after the Earth's surface is invaded by aliens (Space Emigrants, or SE) and humans have been forced to live in underwater cities, the last hope of saving the Earth lies in the hands of five cybernetically enhanced women.
Split into simpler sentences: A hundred years after the Earth's surface is invaded by aliens (Space Emigrants, or SE) and the humans have been forced to underwater cities. The last hope of saving the Earth in the hands of five cybernetically enhanced women.