"If we knew how to communicate with him, we'd go get him instead!" declared Admiral Hausen-Aubier grimly. "There are eight hundred men on the battleship who--"
The Thinking Machine arose, stood staring blankly at the two, much as if he had never seen them before; then walked over to his worktable, and shut off the great electric light.
"It's easy enough to communicate with Prince Otto Ludwig," he said, as he returned to them. "There are half a dozen ways."
"Then why, if it is so easy," demanded the diplomatist, "why hasn't he communicated with his ship?"
"There's always a chance that he doesn't want to, you know," was the enigmatic response. "How many persons know of his disappearance?"
"Only five outside of the secret service and the embassy agents," Admiral Hausen-Aubier answered. "They are Baron Von Hartzfeldt here, the guard, the ship's commander, the ship's surgeon, and myself."
"Too many!" The Thinking Machine shook his head slowly. "However, let's go aboard the Friedrich der Grosse. I don't recall that I've ever been on a modern battleship."
Night had fallen as the three men, each eminent in his own profession, boarded a small power boat off Atlantic Avenue, and were hurried away through slashing waters to the giant battleship in the outer harbor. There for an hour or more the little scientist pottered about the magnificent suite which had been occupied by Prince Otto Ludwig. He asked one or two casual questions of the guard; that was all, after which he retired to the admiral's cabin to write a short note.
"If," he remarked, as he addressed an envelope to Hutchinson Hatch, "if the prince is alive we shall hear from him. If he is dead we will not." His eye chanced upon a glaring headline in a newspaper on the desk:
PRINCE OTTO LUDWIG DANGEROUSLY ILL.
Heir to Throne of Germania-Austria Confined to Suite Aboard the Battle- Ship "Friedrich der Grosse."
No One Permitted to See Him.
The Thinking Machine glanced at Admiral Hausen-Aubier.
"Lies!" declared the rugged old sailor. "Every day for a week it has been the same. We are compelled to issue bulletins. Ach, Gott! He must be found!"
"Please have this note sent ashore and delivered immediately," the scientist requested. "Meanwhile, I haven't been in bed for three nights. If you'll give me a berth, I'll get some sleep. Wake me if necessary."
"You expect something to happen, then?"
"Certainly. I expect a wireless, but not for several hours-probably not until to-morrow afternoon."
"A wireless?" There was a flicker of hope in the admiral's eyes. "May-may I ask from whom?"
"From Crown Prince Otto Ludwig," said The Thinking Machine placidly. "I'm going to sleep. Good night."
Three hours later Admiral Hausen-Aubier in person aroused The Thinking Machine from the lethargy of oblivion which followed upon utter physical and mental exhaustion, and thrust a wireless message under his nose. It said simply:
O.K. Hatch.
The Thinking Machine blinked at it, grunted, then turned over as if to go back to sleep. Struck with some new idea, however, he opened his eyes for an instant.
"Issue a special bulletin to the press," he directed drowsily, "to the effect that Prince Otto Ludwig's condition has taken a sudden turn for the better. He is expected to be up and around again in a few days."
The sentence ended in a light snore.
All that night Admiral Hausen-Aubier, haggard, vigilant, sat beside the wireless operator in his cabinet on the upper deck, waiting, waiting, he knew not for what. Darkness passed, the stars died, and pallid dawn found him there.
At nine o'clock he ordered coffee; at noon more coffee.
At four in the afternoon the thing he had been waiting for came-only three words:
Followed suggestion. Communicate.
"Very indistinct, sir," the operator reported. "An amateur sending."
The Thinking Machine, wide awake now, and below deck discussing high explosives with a gunner's mate, was summoned. Into the wireless cabinet with him came Baron Von Hartzfeldt. For an instant the three men studied in silence this portentous message from the void.
"Keep in touch with him," The Thinking Machine instructed the operator. "What's his range?"
"Hundred miles, sir."
"Strong or weak?"
"Weak, sir."
"Reduce the range."
"I did, sir, and lost him."
"Increase it."
With the receiver clamped to his ears, the operator thrust his range key forward, and listened.
"I lose him, sir," he reported.
"Very well. Set at one hundred." The scientist turned to Baron Von Hartzfeldt and Admiral Hausen-Aubier. "He is alive, and less than a hundred miles away," he explained hurriedly. Then to the operator: "Send as I dictate:
"Is-O-L-there?"
The instrument hissed as the message spanned the abyss of space; in the glass drum above, great crackling electric sparks leaped and roared fitfully, lighting the tense faces of the men in the cabinet. Came dead silence-painful silence-then the operator read the answer aloud:
"Yes."
"Mein Gott ich lobe!" One great exclamation of thanks, and Admiral Hausen-Aubier buried his face in his hands.
To Baron Von Hartzfeldt the whole thing was wizardry pure and simple. The Thinking Machine had summoned the lost out of the void. While a hundred trained men, keen-eyes, indefatigable, wary as ferrets, were searching for the crown prince, along comes this withered, white-faced little man of science, with his monstrous head and his feeble hands, and works a miracle under his very eyes! He listened, fascinated, as The Thinking Machine continued:
"Must-prove-identity-Hausen-Aubier-here-ask-O-L-give-word-or phrase-identify-him."
Suddenly The Thinking Machine whirled about to face the admiral. The answer should prove once for all whether the prince was alive or dead. Minutes passed. Finally--
"It's coming, sir, in German," the operator explained:
"Neujarstag-eine-cigarre."
"New Year's Day-a cigar!" Admiral Hausen-Aubier translated, in obvious bewilderment. Swiftly his face cleared. "I understand. He refers to an incident that he and I alone know. When a lad of twelve he tried to smoke a cigar, and it made him deathly ill. I saved him from--"