Around two o’clock in the afternoon that following day, at a little place called the Creekside Bed & Breakfast, a wonderfully friendly – and admittedly cute – elderly couple named Sylvia and Frank Parkinson came into the lobby to cash in on their reservation.

The high school teenager who welcomed them – a sophomore named Harper Norris, whose parents owned and operated the place – bounced up from a homework assignment she had been attacking online when they came ...