“Boarrrrd! All aboa-”

The conductor’s final warning was drowned out by the engineer signaling Ahead with a majestic double blast on his whistle. Isaac Bell stood up, thinking furiously. John Scully must have been following a suspected spy or saboteur who was headed to San Francisco, where the Great White Fleet would replenish before crossing the Pacific Ocean.

He spoke sharply to the Van Dorn apprentice, who was staring with wide-open eyes at the fallen detective. “Look at me, son.”

The boy tore his gaze from Scully.

“There’s a lot to be done, and you’re the only Van Dorn here who can do it. Round up every witness. Those workmen there, those Chinese fellows with the cart, and these folks hanging about. Someone saw something. This officer will help you, won’t you?”

“I’ll do what I can,” said the cop dubiously.

Bell pressed money into his hand. “Hold them here while this young gentleman telephones Van Dorn headquarters for every available agent. On the jump, son! Then straight back here and get to work. Remember, people are glad to talk if you give them the chance.”

The floor shook. The 20th Century Limited was rolling toward Chicago.

Isaac Bell bolted onto the platform, ran the length of the express train’s red carpet, and jumped.

THIS CALLS FOR A DRINK,” SAID THE SPY.

Some special concoction in honor of Isaac Bell.

Just before the telephone line was disconnected when the 20th Century Limited left Grand Central, Katherine Dee had reported that John Scully had gone to that section of kingdom come set aside for Van Dorn detectives. He cradled the instrument and beckoned an observation-car steward.

“Does your bartender know how make a Yale cocktail?”

“He sure does, sir.”

“Does he have the Crême Yvette?” the spy asked sternly.

“Of course, sir.”

“Bring me one, then-oh, and bring these gentlemen what they would like, too,” he added, indicating a pair of pink-jowled Chicago businessmen who were glowering indignantly. “Sorry, gents. I hope I didn’t thwart any important last-minute telephone calls.”

The offer of a free drink was mollifying, and one admitted, “Just calling the office to tell them I’m on the train.”

His friend said, “Guess they’ll figure that out when you don’t skulk back in moping that you missed it.” Traveling men within earshot laughed and repeated the joke to others who hadn’t heard it.

“Look! There’s a fellow who almost did.”

“He must have jumped!”

“Or flew!”

The spy glanced toward the back of the car. A tall man in a white suit was gliding in from the rear vestibule.

“Maybe he’s got no ticket, figuring to ride the rails.”

“There goes the conductor-on him like a terrier.”

“Guard my cocktail,” said the spy. “I just remembered I have to dictate a letter.”

The 20th Century Limited supplied a stenographer, free of charge. He moved quickly to the man’s portable desk at the head of the observation car, pulled his collar up and his hat low, and sat with his back to the detective. “How soon will a letter I post leave the train?”

“Forty minutes. It will go off at Harmon when we exchange the electric engine for a steam locomotive.” He reached for an envelope engraved VIA 20TH CENTURY. “To whom shall I address it, sir?”

“K. C. Dee, Plaza Hotel, New York.”

“They’ll have it this evening.” The stenographer addressed the envelope, spread a sheet of 20th Century stationery, and poised his pen.

The train was accelerating up the cut that ran north out of the city. Stone walls cast shadows, darkening the windows, causing the glass to mirror the interior of the crowded car. The spy watched Isaac Bell’s pale reflection pass behind him. The conductor trailed solicitously, and it was clear that, ticket or no, Bell was a welcome passenger.

“Ready when you are, sir,” prompted the stenographer.

He waited for Bell and the conductor to pass through the vestibule to the next car.

“‘My dear K. C. Dee,’” he began. He had miscalculated Bell’s reaction to the killing of his fellow detective and underestimated how quickly Van Dorns moved when aroused. Fortunately, he had left Katherine Dee fully prepared to accelerate events. It was simply a matter of unleashing her early.

“Ready, sir?”

“It appears that our customer did not receive our last shipment,” he dictated. “New paragraph. It is imperative that you make a personal visit to Newport, Rhode Island, tonight to set things straight.”

ISAAC BELL HAD PRESENTED Scully’s ticket for upper berth number 5 in Pullman car 6 and asked to pay the extra fare for a stateroom. Informed that every available room was sold out, he had produced a railroad pass. It was signed by the president of a rival line, but competing titans accommodated one another’s personal whims.

“Of course, Mr. Bell. Fortunately, we do have a company suite empty.”

In the privacy of the rosewood-paneled stateroom, Bell tipped the conductor generously.

“With that special pass, you don’t need to tip for good service, Mr. Bell,” said train conductor William Dilber, his hand nonetheless closing like a rattrap around the gold pieces.

Isaac Bell did not need service. He needed an eager associate. He had less than eighteen hours before the 20th Century Limited reached Chicago to find out who killed Scully. No more passengers would board between New York and Chicago. Except Van Dorn detectives.

“Mr. Dilber, how many passengers is your train carrying?”

“One hundred twenty-seven.”

“One of them is a murderer.”

“A murderer,” the conductor echoed tranquilly. Bell was not surprised. As captain of a crack luxury express train, William Dilber was to remain unflappable in the face of derailments, disgruntled tycoons, and snowbound Pullmans.

“You’ll want to see the passenger list, Mr. Bell. Got it right here.”

He unfolded it from his immaculate blue tunic.

“Do you know many of the passengers?”

“Most. We get a lot of regulars. Most from Chicago. Businessmen back and forth to New York.”

“That will help. Could you point out those you don’t know?”

The conductor traced name by name with a clean, manicured fingernail. He was indeed familiar with most, for the 20th Century Limited was very much a rolling private club. The costly excess-fare express drew on the tiny minority of passengers who were extremely well off, and the train ran a proscribed route between New York and Chicago that was fully booked and rarely took on passengers at intermediate stations. Bell saw well-known names in business, politics, and industry, and some famous touring actors. He noted the names of those few Dilber didn’t know.

“I am particularly interested in foreigners.”

“We’ve got the usual handful. Here’s an Englishman.”

“Arnold Bennett. The writer?”

“I believe he is on a lecture tour. Traveling with these two Chinamen. Harold Wing and Louis Loh. They are missionary students, from an English seminary, I believe. Mr. Bennett made a point of telling me personally that he’s their protector in case anyone gives them trouble. I told him it was all the same to me as long as they pay their fare.”

“Did he say what’s he’s protecting them from?”

“Remember that murder last month in Philadelphia? The girl, and all that white-slaving talk in the papers? The police are shadowing Chinamen hot and heavy.”