Complex sentence: Upon reaching Dixon's cell, Sandman turns on and incapacitates him and his followers, and leaves with Dixon's cellmate, a "good egg" who Sandman had deemed deserving of a second chance.
Split into simpler sentences: Upon reaching Dixon's cell, Sandman turns on and incapacitates him and his followers. He then leaves with Dixon's cellmate, a "good egg" who Sandman had deemed deserving of a second chance.