“Still holding at twenty-to-one, sir. A thousand dollars on the Sweetheart of the Air will pay youse twenty thousand.”

“I’ve already bet two thousand.”

“Indeed you have, sir. Admiring your brave sporting instincts, I’m speculating upon the potential value of increasing your initial investment. If the little gal wins, youse can buy yerself a roadster, and a country estate to drive it to.”

Enveloped in clouds of violet cologne, and attended by marble-eyed thugs pocketing the cash and watching for the cops, Johnny Musto was strolling the infield, muttering, “Place yer bets, gentlemen, place yer bets! Odds? Name ’em, they’re yers. One hundred dollars will earn youse fifty if Sir Eddison-Sydney-Thingamajig’s brand-new Curtiss Pusher clocks the best time to San Francisco. Same holds for Frenchie Chevalier driving his Blériot. One-to-two, gents, one-to-two on Chevalier. But if Billy Thomas flies faster for the Vanderbilt syndicate, one hundred will receive one hundred back.”

“How about Joe Mudd? What are the odds on Mudd?” asked a sporting man with a large cigar.

Johnny Musto smiled happily. Clearly, Bell thought, a man blessed by fortune.

“The workingman’s flying machine offers a rare opportunity to win big—three-to-one. Three hundred dollars for a hundred ventured on Joe Mudd. But if you’re looking for a sure thing, bet one hundred dollars on Sir Eddison–So-and-So–Thingamajig and win fifty bucks to take your goil to Atlantic City . . . Hold on! What’s that?” A man dressed in mechanician’s vest and flat cap was whispering in his ear. “Gents! The odds on Sir Eddison–So-and-So–Thingamajig are changing. One hundred will win you forty.”

“Why?” howled a bettor, disappointed to see his potential winnings diminish.

“His chances of beating everybody just got better. His mechanicians chopped the canard off the front of his machine. They found out they don’t need a front elevator, already got one in the back. Sir-Eddison–So-and-So–Thingamajig’s Curtiss Pusher is racing headless. Nobody can beat him now.”

The saboteur had studied it earlier while they were flying it in the last of the evening light, and he had agreed with all in the infield who knew their business that the Curtiss was flying considerably better than before, and somewhat faster. The bookmakers, who were already enamored of the Curtiss Motor Company’s new ninety-horsepower, six-cylinder engine—a reliable “power unit,” by all accounts—led the stampede to declare that the headless Curtiss Pusher was the aeroplane to beat, particularly in the hands of a champion cross-country aviator like the English baronet.

At last the mechanicians covered the machine in canvas shrouds, turned off the generator powering their work lights, and trooped home to their bunks in the train yard. Keeping a sharp eye peeled for roving Van Dorn detectives, the saboteur took a carpenter’s brace and bit from his tool bag and went to work.

The representative of the Aero Club, waiting beside Bell’s machine, gestured impatiently with his clipboard.

Bell vaulted into the American Eagle’s driving seat, tossed his hat to a wing runner, and pulled on his goggles and helmet. “All set!”

He had just finished hammering out last-minute tactics with Harry Warren. Andy and the boys had the monoplane waiting on a grass strip, with the motor warmed and chocks holding the wheels.

“In order to qualify for your pilot’s license, Mr. Bell, you are required to ascend to one hundred feet and fly around the pylon-marked course. Then you will ascend to five hundred feet and remain there ten minutes. Then you will demonstrate three methods of descent: a safe volplane in a series of circles, a gradual ocean-wave downward coast, and a sharper spiral dip. Is that clear?”

Bell grinned. “Is it O.K. if I keep moving while remaining at five hundred feet for ten minutes?”

“Of course. You have to keep moving. Otherwise, the machine will fall. Off you go! I haven’t all day.”

But no sooner had Bell’s motor blatted to noisy life than the rotund Grady Forrer, Van Dorn’s head of Research, galloped through the castor oil smoke, shouting for Isaac to wait.

Bell held down his blip switch. The Gnome sputtered to a grudging stop. Andy Moser brought the soapbox used to climb up to the monoplane. Grady heaved himself on it, saying, “Found out how Frost survived getting shot by you and Archie.”

“Well done! How?”

“Remember I told you that ten years ago a Chicago priest manufactured a so-called bulletproof vest of multiple layers of a particularly tight silk cloth specially woven in Austria?”

“But the Army rejected it. It weighed forty pounds and was hot as Hades.”

“Guess who invested in their manufacture anyway?”

“Chicago,” said Bell. “Of course. Exactly the sort of thing Harry Frost would have gotten a line on and seen its potential. To be bulletproof is a criminal’s dream.”

“And a fellow his size could carry that weight.”

“So the only wound Harry Frost suffered was the jaw Archie broke as he went down.”

“Next time,” said Grady Forrer, “bring a cannon.”

Bell ordered Grady to pass the word to every man on the case. Sidearms—knives, revolvers, and automatics—would not pierce it. Bring rifles. And shoot for the head, just to be on the safe side.

“All right, sir,” he called to the Aero Club certifier. “I’m ready for my test.”

Andy reached to spin the propeller. Bell touched his blip switch. About to shout, “Contact!” he said instead, “Wait!”

“Now what?” exclaimed the Aero Club official.

From the corner of his eye, Bell saw running toward him a hideously scarred young Van Dorn agent from the New York office. Bell signaled Andy, who was reaching to spin the propeller. Andy replaced the wooden soapbox. Eddie Tobin jumped on it and leaned in close so only Bell could hear.

“Looks like they spotted Harry Frost at Saint George.”

St. George, on Staten Island, was a resort town where the Kill Van Kull met the Upper Bay. It was home to grand hotels with beautiful views of New York’s harbor. The busy waterfront served ferries, tugs, coal barges, steam yachts, fishing boats, and oyster scows.

“How sure are you it was Frost?”

“You know some of my folks are in the oyster business.”

“I do,” said Bell without further comment.

For certain Staten Island families, the oyster business extended into realms of activity that the New York Police Department’s Harbor Patrol dubbed piracy. Little Eddie was straight as they came, and Bell would trust the kid with his life. But blood was thick, which made Eddie Tobin an unusually well-informed private detective when it came to the dark side of maritime traffic in the Port of New York.

“A feller who looked a lot like Harry Frost—big, red-faced, gray beard—was flashing money to hire a boat.”

“What kind of boat?”

“He said it had to be steady—wide like an oyster scow. And fast. Faster than the Harbor Patrol.”

“Did he find one?”

“A couple of really fast ones kinda disappeared since then. Both run by fellers who’ll do it for the dough. Frost—if it was Frost—was flashing plenty.”

Isaac Bell slapped his shoulder. “Good work, Eddie.”

The apprentice detective’s face, branded by a brutal gang beating that had nearly killed him, shifted into a lopsided smile. His eyes had survived, though one was partly shaded by a drooping lid, and they glowed with pride at the chief investigator’s compliment.

“Can I ask you what do you think it means, Mr. Bell?”

“If it was Frost—and not some crook trying to smuggle something off a ship or bust his pal out of jail and spirit him off to a friendlier jurisdiction—it means Harry Frost wants a stable gun platform and a fast getaway.”

Bell extracted his long legs from the Eagle’s driving nacelle and leaped out, landing on the grass like an acrobat. “Andy! On the jump!”

“Hold on!” the Aero Club certifier cried. “Where are you going, Mr. Bell? We haven’t even started the test.”

“Sorry,” said Bell. “We’ll have to complete this another time.”

“But you must hold your certificate to enter the race. It’s in the rules.”

“I’m not in the race. Andy! Paint her yellow.”

“Yellow?”

“Whiteway Yellow. The same yellow as Josephine’s. Tell her boys I said to give you as much dope as you need and to lend a hand with the brushes. I want my machine yellow by morning.”

“How are people going to tell you apart? Your machines look near the same already. It’s going to be very confusing.”

“That’s the idea.” said Isaac Bell. “I’m not making this easy for Harry Frost.”

“Yeah, but what if he shoots at you thinking you’re her?”

“If he shoots, he’ll reveal his position. Then he’s all mine.”

“What if he hits you?”

Isaac Bell didn’t answer. He was already beckoning his detectives and addressing them urgently. “Young Eddie’s turned up a heck of a clue. Station riflemen on boats on the East River and the Upper Bay and up the Hudson all the way to Yonkers. We’ve got Harry Frost where we want him.”