In an ambitious scientific endeavor, two pioneering researchers bring a Neanderthal back to life—the first to exist in approximately 35,000 years—in hopes of finding answers to profound questions. This being, named William, is both a typical child and a scientific project, leaving his ‘parents’ grappling with how to nurture him. As William matures, he learns about human emotions such as love and intimacy. However, as he attempts to fit into human society, his primal instincts start to surface, resulting in devastating outcomes for both him and those around him.