
Geoffrey Falconer, a freshly demobilised RAF officer turned experimental scientist, spends his evenings in a secluded laboratory tucked beneath his family’s ivy‑clad manor in Essex. There he has built an ultra‑sensitive wireless receiver, enhanced with his own secret microphone amplifier, that catches a strange, non‑Morse signal exactly at 7:18 p.m. each night—three repetitions of a baffling note that no one else seems to hear. As the clock ticks, Geoffrey pores over his diary, trying to determine whether the tone is a natural phenomenon, a distant transmission, or something far more deliberate.
The story unfolds in the atmospheric world of early twentieth‑century wireless research, where brass knobs, glowing tubes, and tangled wires create a backdrop of both nostalgia and cutting‑edge invention. Geoffrey’s lineage—son of a retired Oxford professor and heir to a historic Georgian house—adds a layer of expectation and responsibility to his quest. Listeners are drawn into his methodical investigation, the quiet tension of a mystery that repeats night after night, and the promise of uncovering a secret that could change more than just his experiments.
Language
en
Duration
~7 hours (426K characters)
Publisher of text edition
Project Gutenberg
Credits
Produced by Tim Lindell, David E. Brown, and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive/American Libraries.)
Release date
2019-05-04
Rights
Public domain in the USA.

1864–1927
A hugely popular early master of spy fiction, he turned fears of invasion and international intrigue into fast-moving stories that gripped readers before the First World War. His books helped shape the mood of his age, mixing journalism, suspense, and a flair for dramatic danger.
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