It began in the fields when the year was dying. The Celts called it Samhain—a night when the border between worlds turned porous as breath. Fires burned on the hills; the living disguised themselves to fool the dead, who wandered freely, homesick for warmth. Cattle were slaughtered, hearths were blessed, and every shadow felt personal. It was the year folding itself shut. Centuries later, the Church pressed its seal upon the fire. All Hallows’ Eve, they called it, the eve of saints and souls. But the fire would not behave. It danced in doorways and behind church glass, wild as memory. The saints stayed in their windows; the ghosts stayed in the streets. Years passed, and the night put on different masks. Lanterns carved from turnips. Apples bobbing in water. Faces painted white. It crossed oceans, found new soil, learned new songs. The fields became suburbs. The bonfires became doorbells. The disguises, more flattering. But the impulse—the small, lovely terror of being seen and n...