John Constantine, a troubled man with the unique ability to see and communicate with angels and demons among humans, walks a gray line between heaven and hell. Mortally marked with lung cancer and haunted by the fate of his eternal soul due to a suicide attempt, Constantine seeks redemption by battling demonic entities that cross into the human realm. His world-weary attitude and unorthodox methods pit him against both supernatural threats and skeptics from the human police force. Despite his jaded exterior, Constantine is driven by a deep-seated desire to do good, even if his means are often questioned.

When police detective Angela Dodson approaches Constantine for help in investigating the mysterious suicide of her twin sister, Isabel, their inquiry unveils a much larger and darker plot that threatens the balance between heaven and hell. As they delve deeper into a world populated by demons, angels, and other paranormal beings, the pair confronts challenges that test their beliefs and understanding of the world beyond our own. Their journey together not only seeks to solve the mystery of Isabel’s death but also forces Constantine to confront his past and question his own faith and purpose.