The shift to Isaac and Constantine as the central pairing is fully justified by the series architecture; both characters have been visible enough in prior books that their romance reads as continuation, not detour. Isaac’s recovery arc is handled with specificity: sober Isaac is not simply better Isaac, but a man learning to navigate desire, trust, and purpose without the chemical buffer he relied on for years. Constantine’s backstory in ancient Gaul pays structural dividends when the ancient evil threatening his clan connects to his own history. What keeps this from matching the tightest entry is a pacing imbalance in the back half, where the threat resolution moves faster than the emotional work around it strictly warrants; the romance earns its place, but the plot wraps with less weight than it built.