Tyler's mundane life takes a dark turn when he discovers an ancient, powerful book, "Liber Infernus," on the last day of school. Unable to harness its abilities initially, he rejects it, only to regret his decision later.

Fate grants Tyler a second chance, reincarnating him to the moment of refusal. Now the keeper of the forbidden tome, he transforms into a demon to unlock its secrets. On a perilous journey to recreate forgotten inventions, Tyler teeters on the edge of humanity. The line between savior and harbinger of doom blurs as he battles against his own demonic desires, risking the very fate of humanity!