When Mayguard Manor, an abandoned Gothic castle rising from the icy waters of Lake Superior, reopens for its first event in over fifty years, it promises an unforgettable destination wedding. For neurosurgeon Amber Tambon, it's meant to be a fresh start: her fourth engagement, a younger fiancé, and a chance to finally outrun a past shaped by emotional distance and relentless ambition.

But Mayguard has a history steeped in tragedy. The former owners and one of their adopted children died within its towers. Bridges have collapsed without warning. And now, as wedding guests begin arriving, death returns, the first victim a ferry operator, burned alive in one of the castle's towers. A notorious pyromaniac serial killer resurfaces, marking each victim with a single maroon taper candle. As guests vanish and a violent storm seals off the island, every escape route disappears as panic ignites.

Amber, haunted by her own exposure to the killer's victims through her work at the hospital, finds herself forced into the center of the nightmare. As bodies accumulate and the castle's dark past begins to mirror the present, it becomes clear the murders are not random. Each death is deliberate. Ritualistic. Personal.

Secrets unravel among the wedding party-fractured marriages, buried trauma, and long-standing resentments surface under pressure. The line between victim and suspect blurs as Amber realizes the killer may be using the wedding itself as the final act in a carefully staged performance.

With fire spreading, time running out, and the maroon candle appearing closer and closer to her own door, Amber must confront the castle's truth and her family's tie to the unfolding terror before Mayguard Manor claims everyone inside.