An angel and a demon work together to solve paranormal crimes on the mortal plane.
They met because of a human, the angel’s charge and the demon’s love. The demon abandoned Hell when they fell for the human. The human died under suspicious circumstances that the guardian angel wasn’t able to prevent. Riddled with guilt and the feeling of failure, the angel fell from heaven.
Both desperate to save someone in an attempt to cope with being unable to save the person they both loved, the angel and demon team up and begin solving supernatural crimes.
A few months down the line, they run into a pandemic of soulless, reanimated corpses. In an attempt to uncover the necromancer responsible for the plague of zombies, they reconnect with an old friend, a witch they lost touch with after the human died.
As the angel and demon struggle to narrow down suspects, they discover that one of the people reanimated is the human they both cared for.
Turns out, their witch friend had been the necromancer responsible all along, and it all began with her trying to save the human and bring them back after they died. All of the monstrous zombies she’d created in the process were fruitless attempts to get her friend back.