A dead surveyor. A corrupted compass. And buried iron that points to murder.

Nevada Territory, 1882. Surveyor Virgil Peck is found face-up on the alkali flats east of Furnace Creek — no water, no hat, no horse, and a shattered compass at his side. The coroner rules it exposure. The desert, after all, doesn't require malice.

Silas Thorne knows better.

Hired to verify Peck's railroad survey, Silas and his partner Linus arrive in a town built around a water tower and controlled by a man who owns every spring in the basin. The survey should be routine. But Silas's theodolite finds a four-degree compass error at every monument — an error that shifts the section boundaries just far enough to place three desert springs on the wrong side of a barbed-wire fence.

Someone buried iron in the ground to make the compass lie. And someone killed the man who found it.

With a telegraph operator whose memory files every face and every message, a rancher whose cattle haven't reached water in fourteen months, and a railroad superintendent who needs the survey settled before the tracks arrive, Silas must excavate the fraud one monument at a time — using the sun to prove what the compass cannot.

But the deeper Silas digs, the closer the case cuts to his own search for his missing father. A telegram from eighteen months ago bears the name Continental Surveying Associates — an echo of the firm his father founded and that vanished when he did. The trail and the commission are no longer running parallel. They're running through each other.

The Iron Meridian is the fifth book in the Thorne & Linus: Cartographic Mysteries series. Each book is a complete, standalone mystery. Series listeners will find the deeper story they've been following since Promise Creek.

For listeners who love historical mysteries with real frontier settings, fair-play puzzles, and the partnership of two men who measure the truth for a living.