near to taking the ginger all out of me, captain," breathed Matt. "The novelty of the thing was mighty trying."

Captain Nemo, Jr., still strangely pale, was regarding the youth fixedly. For some moments after the cheering ceased he said nothing; then, leaning abruptly forward, he caught Matt's hand.

The captain's flesh was as cold as ice.

"Captain!" the young motorist exclaimed, starting up, "there's something wrong with you! Do you feel——"

The captain waved his hand deprecatingly, and the calm, inscrutable smile hovered about his thin lips.

"Let that pass for a moment, my lad," said he. "I was testing the Grampus, but, more than that, I was likewise testing you. Since we picked up Carl and Dick, off the Dolphin, and before that, while we were cruising about trying to find them,[A] you have been serving your apprenticeship on the submarine. I have always had the utmost confidence in you, Motor Matt, and I have now, I think, tested your knowledge of the Grampus in a manner which leaves no room for doubt. You are able to run the boat, and to extricate her from any difficulties in which she might become entangled, as well, if not better, than I could do myself."

Matt, from the captain's manner, had suspected that the gray-haired inventor of the craft had tried to bring out all that was in him. Captain Nemo, Jr., of course, had not been able to forecast the trouble that was to overtake the submarine in the bottom of the bay, but this dangerous experience had served only to show Matt's resourcefulness to better advantage.

"You are cool-headed in time of danger," proceeded the captain, "and, no matter what goes wrong, your ability is always on tap and can be brought to bear instantly upon anything you desire to accomplish."

The red ran into Matt's face and he waved a hand deprecatingly.

"I'm not a particle better than a lot of other fellows," said he, "who try to use their eyes, and hands, and brains."

"I expected you to say that, Matt," continued the captain. "The test, in your case, was hardly necessary, for I have watched your work in a lot of trying situations—and it has always been the same, steady, resourceful, reliable. Just now, we are going to Belize, British Honduras, to carry out some work for our government. As I have already told you, I don't know what that work is. Two sealed envelopes were given me by Captain Wynekoop of the U. S. cruiser Seminole. The first one told us to proceed to Belize. The next one, which I have here in my pocket, will instruct you relative to the work in prospect, and——"

"Instruct me?" broke in Matt, startled.

The captain nodded.

"I have not recovered from the strange illness which overtook me in New Orleans, as a result of inhaling the poisonous odor given off by the head of that idol. I feel that another attack is coming upon me—I have felt it for several hours—and, inasmuch as the government is watching the work of the Grampus with the intention of buying her at a good round price if she makes good, our sealed orders must be carried out. For this work, Matt, you are my choice; you are to command the Grampus, do everything that you think—that you think——"

Captain Nemo, Jr., paused, struggled with the words for a space, then drooped slowly forward and fell from his seat to the floor of the room. There he lay, unconscious and breathing heavily.

CHAPTER III.

THE SEALED ORDERS.

For a brief space Motor Matt and Cassidy stood looking down at the prostrate form crumpled at their feet. The captain had been stricken so suddenly that they were astounded.

Cassidy took a look through the periscope and lashed the wheel; then he hurried to help Matt, who was lifting the unconscious man to a long locker at the side of the room.

"He ain't never been right since he was sick in New Orleans," muttered Cassidy. "He jumped into work before he was well enough."

The captain's former illness had been of a peculiar nature. An idol's head, steeped in some noxious liquor that caused the head to give off a deadly odor, was, according to his firm belief, the cause of his sickness. Carl had also come under the influence of the poisonous odor, but it had had no such effect upon him. However, no two persons are exactly alike, and sometimes a thing that will work havoc with one may have no effect upon another.

"His heart action is good, Cassidy," said Matt.

"He's a sick man for all that," replied the mate. "I've noticed for several hours he was nervous like. We'll have to take him ashore at Belize, and you'll have to be the captain while we're doing the work that's to be done."

There was an under-note in Cassidy's voice that caused Matt to give him a keen look. The mate was a good fellow, but he was second in command, aboard the Grampus, and it was quite natural for him to expect to be the one who stepped into the captain's shoes.

"You heard what Captain Nemo, Jr., said?" asked Matt.

"Sure, I did," returned the mate gruffly.

"I had not the least notion he was picking me for any such place."

"He's a queer chap, the cap'n is," said Cassidy, averting his face and getting up from the side of the locker. "I'll go get him a swig of brandy—maybe it'll bring him round."

When Cassidy returned from the storeroom with the brandy flask, Matt could hardly avoid detecting that he had himself sampled the liquor. Matt was disagreeably surprised, for he had not known that the mate was a drinking man.

While they were forcing a little of the brandy down the captain's throat, Dick and Carl came into the periscope room.

"Vat's der madder mit der gaptain?" asked Carl, as he and Dick crowded close to the locker.

Matt told of the illness that had so suddenly overtaken the master of the submarine.

"Shiver me, but it's main queer!" exclaimed Dick.

"For the last hour," went on Matt, "the captain's hands have been like ice and his face pale. I knew he didn't feel well, but I hadn't any idea he was as bad as this."

"Tough luck!" growled Cassidy.

"Will we need a pilot to take us into Belize?" asked Matt.

"We can't get very close to the town, but will have to lay off and go ashore in a boat. I know the place well enough to take the Grampus to a safe berth."

"Then you'd better go up in the lookout, Cassidy, and see to laying us alongside the town."

A mutinous look flickered for an instant on Cassidy's weather-beaten face. He hesitated, and then, without a word, turned away and climbed into the conning tower.

A moment more and the captain had revived and opened his eyes.

"How are you feeling, sir?" queried Matt.

"Far from well, my lad," was the answer, in a weak voice. "Are we off Belize?"

"Not yet, sir, but we are drawing close."

"We are close enough so that we can read the second half of our sealed orders."

The captain lifted a hand and removed from the breast pocket of his coat a sealed envelope, which he handed to Matt.

"Open it, Matt," said he, "and read it aloud."