Abstract: An electric lock comprises a bolt that is movable into and out of a specially-shaped keeper. The bolt is displaced relative to a casing by a motor that is in turn slidably mounted within the casing. During normal use, the motor is fixed relative to the casing by an electromagnetic, and urged away from the electromagnet by a spring that is weaker than the electromagnet. When the power supply to the lock is intentionally or unintentionally cut off, the spring thus urges the motor, and with it the bolt, away from the electromagnet, thereby automatically opening the lock.