The blue flame was a lie. It was the last, guttering spark of Agnetha’s power, a final piece of theatrical defiance that consumed itself into nothingness after a few heart-pounding seconds. But the damage was done. The psychological scar remained. Every flicker of a candle, every pilot light on a stove, would now carry the ghost of that dread for a long time.

The cleanup was a monumental task, a blur of bureaucratic incantations and physical labor that stretched for ...