“It can be managed by a sort of weighted relay. Contacts are closed when the lightening spell is active, held there by a spring. If the spell wears off, the weight on the contact is too heavy for the spring, and they open. Cuts the signal to unlock. If they roll upside-down or some other maneuvers it may close again, but that’s a much slimmer chance of an already slim chance, or a conscious action on their part.”