Complex sentence: Matt and the other three desperately need to find Scarlett Adams, the final Gatekeeper, who has been trapped in Hong Kong, where shape-changers and possessed humans stalk the street calamity befalls Hong Kong and hope soon turns black for humanity.
Split into simpler sentences: Matt and the other three desperately need to find Scarlett Adams, the final Gatekeeper, who has been trapped in Hong Kong, where shape-changers and possessed humans stalk the streets. Calamity befalls Hong Kong and hope soon turns black for humanity.