The Mystery Message

The early summer morning was warm and very quiet, and the only sound in the bare, barn-like room was the slow sucking of waves at the foot of the granite cliff on which it was built. On the table in the center of the room was a wireless device with five valves, the wires through which passed through the roof. Two thin cords dangled near the wires, the lower ends of which were within the reach of Jim Selvin, a tall, slender boy with a sharp face, who was sitting with headphones in his ears.