Frequency Unknown

Twelve-year-old Leo builds a ham radio for the science fair and picks up a mysterious signal — his own voice, from 48 hours in the future, warning him about something terrible at school. Can he change what is coming?

Leo tightened the last wire on his homemade ham radio and leaned back in his desk chair with a grin. The science fair was on Thursday — just three days away — and his project was finally done. The radio sat on his desk surrounded by soldering tools, copper wire, and a dog-eared electronics manual.

His bedroom window was cracked open, letting in a warm Tuesday evening breeze. The antenna he had strung from his window to the oak tree in the backyard swayed gently in the wind.