Imagine walking through a field on a cloudless day when you suddenly hear the 130-decibel roar of a fighter jet. But you can’t spot the jet, or even tell which direction the sound is coming from.

You’ve been holed up in a trench for weeks, fighting a desperate battle against unknown odds. Suddenly, you’re bathed in an pulsing, eerie ball of light. Then you hear a disembodied voice ... “Lay ...