Bell could not ignore such mystery about a man who had the run of the air race infields and was welcomed in every hangar car. Particularly since Dmitri Platov had volunteered to fill in for Eddison-Sydney-Martin’s murdered mechanician days before the Englishman’s propeller broke loose and smashed him into a Kansas creek. And if there was any one mechanician in the race who knew his business, it was Platov.

The researchers’ preliminary report, wired back in half a day, was baffling.

The only information on Dmitri Platov was found in Van Dorn files that contained newspaper clippings about the Whiteway Cup preparations at Belmont Park, and Isaac Bell’s own reports from the infield. Similarly, newspaper reporters had described, with varying degrees of accuracy, Platov’s revolutionary thermo engine, but only in articles about its destruction in the accident that had killed Steve Stevens’s chief mechanician.

Bell pondered the meaning of such a lack of information. It jibed with Danielle Di Vecchio’s assertion that she had never met Platov at the International Aeronautical Salon in Paris nor even heard his name there.

Was it possible that Platov had never been at the Paris air meet? But if he had not been in Paris, then from whom had Marco Celere bought his so-called jet engine?

Bell wired Research:

CONCENTRATE ON THERMO ENGINE.

ON THE JUMP!

Then he called Dashwood into his headquarters car. “I’m taking you off the gamblers. Watch Dmitri Platov. Don’t let him know, but stick to him like his shadow.”

“What am I looking for?”

“He’s making me uncomfortable,” said Bell. “He could be as innocent as he looks. But he had the opportunity to sabotage the Englishman’s pusher.”

“Could he be Harry Frost’s inside man?” asked Dashwood.

“He could be anything.”

ISAAC BELL HALED the few Van Dorns in the Southwest he could get his hands on to defend Josephine’s wedding from Harry Frost’s Colt machine guns. As the private detectives hurried into Fort Worth and reported aboard the Eagle Special, he drummed in his strategy: “Make it impossible for Harry Frost to sneak close enough to do damage. Ransack your contacts. There are darned few of us, but if we pool our links to lawmen, railroad police, informers, gamblers, and criminals beholden to us, we can try to establish a perimeter equal to the Colts’ range and keep him outside it.”

The stolen Colts’ long range was the threat. The machine guns were deadly up to a mile. But Frost could nearly treble the threat by elevating the barrels to loft indirect “plunging fire,” where bullets would rain down on the party indiscriminately from a distance as great as four thousand five hundred yards—the better part of three miles.