Complex sentence: She also has a dark secret that not even she knows about at first, for within her lie the genes that hold the next step in the evolution of mankind, the same blood as the beast-like superhumans that terrorize the city.
Split into simpler sentences: She also has a dark secret that not even she knows about at first, for within her lie the genes that hold the next step in the evolution of mankind. The same blood as the beast-like superhumans that terrorize the city.