He held patents for an invention he named the Electrical Vacuum Cleaning Machine, having hitched his fertile imagination to a heartfelt notion that science-based domestic engineering could free women from the isolation of housework. He also believed that women should have the right to vote, work outside the home, and even practice birth control. Gossips smirked that his beautiful daughter, who ran with the fast set in Washington and New York, would be a prime beneficiary.

“A one-man lunatic fringe,” complained the commandant of the navy yard.

But the chief of Naval Ordnance, having observed Langner’s latest 12-inch/.50 caliber gun shoot up his Sandy Hook Atlantic Test Range, retorted, “Thank God he works for us instead of the enemy.”

His Sunday-morning chamber musicians, a ragtag mix of Gun Factory employees, laughed appreciatively when Langner joked, “Just to assure any eavesdropping blue noses that we’re not complete heathens, let’s start with ‘Amazing Grace.’ In G.”

He sat at his grand piano.

“May we please have an A first, sir?” asked the cellist, an expert in armor-piercing warheads.

Langner lightly tapped middle A, to which note the strings could tune their instruments. He rolled his eyes in mock impatience as they fiddled with their tuning pegs. “Are you gentlemen cooking up one of those new atonal scales?”

“One more A, if you can spare it, Arthur. A little louder?”

Langner tapped middle A harder, again and again. At last the strings were satisfied.

The cellist began the opening notes of “Amazing Grace.”

At the tenth measure, the violins—a torpedo-propulsion man and a burly steamfitter—took up “once was lost.” They played through and began to repeat.

Langner raised his big hands over the keys, stepped on the sustain pedal, and lofted “a wretch like me” on a soaring G chord.

Inside the piano, Yamamoto Kenta’s paste of nitrogen iodide had hardened to a volatile dry crust. When Langner fingered the keys, felt hammers descended on G, B, and D strings, causing them to vibrate. Up and down the scale, six more octaves of G, B, and D strings vibrated sympathetically, jolting the nitrogen iodide.

It exploded with a sharp crack that sent a purple cloud pouring from the case and detonated the sack of Cordite. The Cordite blew the piano into a thousand slivers of wood and wire and ivory that riddled Arthur Langner’s head and chest, killing him instantly.

2

BY 1908, THE VAN DORN DETECTIVE AGENCY MAINTAINED a presence in all American cities of consequence, and its offices reflected the nature of each locality. Headquarters in Chicago had a suite in the palatial Palmer House. Dusty Ogden, Utah, a railroad junction, was served by a rented room decorated with wanted posters. New York’s offices were in the sumptuous Knickerbocker Hotel on 42nd Street. And in Washington, D.C., with its valuable proximity to the Department of Justice—a prime source of business—Van Dorn detectives operated from the second floor of the capital city’s finest hotel, the new Willard on Pennsylvania Avenue, two blocks from the White House.