Hell plays dirty, but Heaven can't. At times Heaven needs to get its hands dirty too and that's when they call on Heaven's Darkside. Led by the Metatron, a motley crew consisting of a former Viking, a tattoos artist, and a weapons expert with an unknown past, band together to form the splinter cell team for Heaven. Their mission is to find three members of the Fallen-former Angels deposed to Hell after following Lucifer. Through backchannels, Heaven is alerted to their presence on Earth, but is not made aware of exactly where to find them. Atavist, the largest defense corporation in the world seemed to spring up overnight. Originally based out of the United States, they branch themselves off the highest bidder now, expanding internationally and diversifying into prostitution and black market deals. Unknown to Heaven, they are led by the three members of the Fallen that Heaven's Darkside is tasked to find. Dedicated to bring Hell to Earth, Atavist is determined to take out Heaven's Darkside to prevent their plans from being thwarted. With the help of another player in the field, Heaven's Darkside battles their way to the top, only to be shocked by the outcome. Who will survive? Is everyone really who they appear to be?