Dog-Days began about the 20th of July. Before that the dwellers in Camp Spurling had experienced occasional spells of fog, but nothing very dense or long-continued. Now they got a taste of the real thing. They were dressing fish on the Barracouta one afternoon when a cold wind struck from the southeast.

Spurling held up his hand.

"We're in for it!" said he. "Feel that? Right off the Banks! In less than an hour we'll need a compass to get ashore in the dory."

He was so nearly right that there was no fun in it. The wind hauled more to the east, and in its wake came driving a gray, impenetrable wall. The ocean vanished. The points on each side of the cove were swallowed up. Quickly disappeared the cove itself, the beach, the camp and fish-house, and the bank beyond them. The sloop was blanketed close in heavy mist.

Jim made a pretense of scooping a handful out of the air and shaping it like a snowball.

"Here you go, Budge!" he exclaimed. "Straight to third! Put it on him! Fresh from the factory in the Bay of Fundy! If this holds on until midnight, we won't be able to see outside our eyelids when we start trawling; there's no moon."

"Will you go, if it's thick as it is now?" inquired Lane.

"Sure! Here's where the compass comes in. If we stayed ashore for every little fog-mull, we wouldn't catch many hake the next six weeks. This isn't a circumstance to what it is sometimes. I've known it to hang on for two weeks at a stretch. Ever hear the story of the Penobscot Bay captain who started out on a voyage round the world? Just as he got outside of Matinicus Rock he shaved the edge of a fog-bank, straight up and down as a wall. He pulled out his jack-knife and pushed it into the fog, clean to the handle. When he came back, two and a half years later, there was his knife, sticking in the same spot. He tried to pull it out, but the blade was so badly rusted that it broke, and he had to leave half of it stuck in the hole."

"Must have had some fog in those days!" was Lane's comment. "Did you say this all comes from the Bay of Fundy?"

"Not all of it. Fog both blows and makes up on the spot. Sometimes it rises out of the water like steam. I've heard my uncle say that Georges Bank makes it as a mill makes meal. It's worst in August. Then the smoke from shore fires mingles with it; and the wind from the land blowing off, and that from the sea blowing in, keep it hazy along the coast all summer."

Jim's predictions proved correct, as they generally did. While there were occasional stretches of fine weather during the next few weeks, the fog either hovered on the horizon or lurked not far below it, ready to bury the island at the slightest provocation in the way of an east or southeast wind. Despite its presence, the routine of trawling and lobstering went on as usual. Every Friday came the regular trip to Matinicus to dispose of the salted fish and procure groceries, gasolene, and salt, as well as newspapers and mail.

On each of these visits Percy always weighed himself on the scales at the general store. Beginning at one hundred and thirty-five, he climbed steadily, pound by pound, toward one hundred and fifty. An active, out-of-door life, combined with regular hours and a simple, wholesome diet, together with the exclusion of cigarettes, resulted inevitably in increasing weight and strength. At the close of each afternoon he climbed the bluff with his sweater stuffed with rockweed. The others joked him considerably about these mysterious trips, but failed to extract any information from him regarding them. When he chose, Percy could be as close-mouthed as his father.

At about this time a letter from the millionaire reached his son through the Matinicus office. It bore the postmark of San Francisco, and ran as follows:

It actually surprised Percy to find out how glad he was to receive this laconic epistle from his only living relative. He cast about for a suitable reply.

"I want to send something that'll please him," he thought. "He hasn't had much satisfaction, so far, out of me."

Finally, after mature deliberation, he indited the following:

The Three Musketeers gathered dust on the wooden shelf. Percy had faced squarely the fact of his college conditions, and had determined that they must be made up at the opening of the fall term; so his spare time went into Virgil and CÆsar and algebra and geometry, instead of being spent on Dumas. He rarely asked for assistance from the others; they had little leisure, and it was his own fight. He buckled down manfully.

Another task that he set before himself was the establishment of cordial relations with the other members of the party. He realized that his own fault had made this necessary. It had been an easy matter to get on good terms with Jim, Budge, and Throppy. With Filippo it was a little harder; but soon he, too, thawed out when he found that Percy treated him courteously and was willing to do his share of the camp work. Even Nemo wagged his tail when Percy appeared, and the crow grew tame enough to eat fish out of his hand.

One afternoon, when the fog had lifted sufficiently to make it possible to see a few hundred feet from the island, a motor-boat unexpectedly appeared from the north and swung round Brimstone Point into the cove. She ran up alongside the Barracouta, where the boys were baiting their trawl.

"I'm the warden," said one of the two newcomers, a gray-mustached, keen-eyed man. "I've come to look over your car."

Jim took his dip-net and stepped into the motor-boat, and they ran up to the lobster-car. A few minutes' investigation of its contents satisfied the official that it contained no "shorts."

"Glad to be able to give you a clean bill of health," said he as he set Jim back on board the sloop. "I wish some other people I know of did business as clean and aboveboard as you young fellows."

A quarter-hour later the sound of his exhaust had died away in the fog to the northward.

"What would he have done if he'd found any 'shorts'?" asked Percy.

"Fined us a dollar for every one," answered Jim. "Taken the cream off the summer, wouldn't it? Sometimes it pays, even in dollars and cents, to be honest."

The next morning was hot and muggy. The sea about the island was clear of fog for one or two miles. Jim and Budge had started long before light to set the trawl, and Throppy wished to make some changes on his wireless; so Filippo was glad enough of the chance to go out with Percy to haul the lobster-traps.

The little Italian had lost much of his melancholy. He enjoyed his work and the good-fellowship of the camp. The weeks of association with his new friends had made of him an entirely different fellow from the lonely, homesick lad they had picked up on the steamboat wharf at Stonington.

The two boys started in the pea-pod at six o'clock. A glassy calm overspread the sea. Even the perpetual ocean swell seemed to have lost much of its force.

"I'll row!" volunteered Percy.

He stripped off his oil-coat and sweater and rolled up his shirt-sleeves.

"It'll be hot up in the granite quarries to-day, hey, Filippo? S'pose you're sorry not to be there?"

"Io sono contento" ("I am satisfied"), replied the Italian.

Hauling and rebaiting the hundred-odd traps was a good five hours' job and more for the couple, neither of whom had ever handled a small boat or seen a live lobster before the previous month. As the forenoon advanced the air seemed to grow thicker and more breathless. Over the water brooded a languid haze, through which the sun rays burned with a moist, intense heat.

Percy's bare arms began to grow red and painful.

"Feel as if they were being scalded," he complained. "I've heard Jim say a fog-burn was worse than any other kind. Now I know he's right."

Eleven o'clock, and still twenty-five traps to be pulled. Most of these were on the Dog and Pups, a group of ledges more than a mile northeast of the island. It was the best spot for lobsters anywhere about Tarpaulin. Percy hesitated.

"Fog seems to be closing in a little," he observed, "and we haven't any compass. Should hate to get out there and have it shut down thick. Might be hard work to find the island again."

He glanced at the tub of lobsters.

"If the Dog and Pups keep up anywhere near their average, we'll beat the record. What d'you say, Filippo? Shall we take a chance and surprise the rest of 'em?"

Filippo flashed his white teeth.

"I go with you," he smiled.

"Then go it is!" decided Percy.

He headed the pea-pod for the Dog and Pups.

"We'll keep a sharp lookout, and if it starts to grow anyways thick we'll strike back for old Tarpaulin."

A pull of about twenty minutes brought them to the ledges, around which the traps were set in a circle. They began hauling at the point in the circumference nearest to the island, following the buoys west and north. The catch exceeded their hopes.

"We'll need another tub, if this keeps up," chuckled Percy.

Filippo laughed jubilantly. The fog was forgotten. Their entire attention was centered on the contents of each trap as it was pulled.

Round on the edge of the circle farthest from the island a pot refused to leave bottom. Percy tugged till he was red in the face, but he could not start it.

"Catch hold with me, Filippo!" he puffed.

The Italian joined his strength to Percy's, but to no avail. The slacker still clung to the bottom. The boys straightened up, panting.

"We'll have to leave it," acknowledged Percy, disappointedly. "Probably there's half a dozen two-pound lobsters in it."

He looked about and gave a startled cry.

"Where's the island?"

The wooded bluffs of Tarpaulin had disappeared. While they had been wrestling with the stubborn trap the fog had stolen a march on them. On all sides loomed a horizon of gray mist, not a half-mile distant and steadily drawing nearer. They must locate the island and get back to it at once.

Percy tossed over the buoy and the warp at which they had been pulling. Tarpaulin lay southwest; but which way was southwest? Busied with the trap, he had utterly lost all sense of direction. The sun? He glanced hopefully up. No; that would not help any. The fog was too dense. Ha! The surf?

"Listen hard, Filippo!" he exhorted.

They strained their ears. No sound. The swell was so gentle that it did not break on the ledges of the island loudly enough to be heard a mile and a quarter off. The heaving circle of which they were the center was contracting fast. Its misty walls were now less than five hundred feet away.

"Guess we'd better take a buoy aboard, and hang to it till Jim comes out to hunt us up. It'd make me feel cheap to do it, but it's the only safe way. But wait! What's that?"

Both listened again. A sound reached their ears, plain and unmistakable, the rote of dashing water.

"There's the surf!" rejoiced Percy. "Don't you hear it?"

"Si, I hear it," answered Filippo.

Dropping the buoy he had just gaffed, Percy took the oars and began rowing hard toward the sound, which gradually grew louder. The fog came on with a rush, sliding over them like an avalanche. It was hardly possible to see beyond the tips of the oar-blades.

"Lucky we can hear that surf!" said Percy, comfortably. "But strange it sounds so loud and so near."

Now it was close ahead. He stopped rowing, puzzled. A blast of cold air smote them. Suddenly there was a rushing all around. It was not the surf at all, but waves, breaking before the coming wind. They were lost in the fog!

Percy faced Filippo blankly. For a moment his head went round. With bitter regret he now realized that in dropping the buoy he had given up a certainty for an uncertainty that might cost them dearly. But nothing was to be gained by yielding to discouragement. He reviewed his scanty stock of sea lore.

"That wind is probably blowing from some point between northeast and southeast. If we turn around, and run straight before it, we'll be likely to hit the island."

He swung the pea-pod stern to the breeze.

"Here goes! Watch out sharp for lobster-buoys, Filippo!"

But no buoys appeared. They might pass within ten feet of one and never see it. Five, ten, twenty, thirty minutes passed; and still no sign of Tarpaulin. The wind was becoming stronger, the waves higher; their rushing was now loud enough to drown the sound of any surf that might be breaking on the ledges of the island. Percy rowed for a quarter-hour longer, dread plucking at his heart-strings. At last he rested on his oars.

"We've missed it," he acknowledged, despondently.

They were lost now in good earnest. It was one o'clock. The fog hung over them like a heavy gray pall, so damp and thick that it was almost stifling. Percy turned the pea-pod bow to the wind and began rowing again.

"We must try to hold our own till it clears up," he observed, with attempted cheerfulness.

But his tones lacked conviction. It might not clear for two or three days. By degrees his strokes lost their force, until the oars were barely dipping. The boat was going astern fast.

Two o'clock. Long ere this Jim and Budge must have returned from trawling and realized that the pea-pod and its occupants were lost. They were probably searching for them now, perhaps miles away on the other side of the island, wherever it might be.

A gruff bark startled them. A round, black, whiskered head suddenly thrust up out of the water close to the port gunwale. Filippo cried out in alarm, but Percy reassured him.

"Only a seal!"

Abruptly the sea grew rough. All around them tossed and streamed and writhed long, black aprons of kelp. They were passing over a sunken ledge. Soon it lay behind them; the kelp vanished and the waves grew lower.

Three o'clock went by; then four. The afternoon was waning. The thick, woolly gray that surrounded them assumed a more somber shade. Night was coming, pitchy and starless, doubly so for the two lost boys, adrift on the open ocean.

Hark! What was that? They both heard it, far distant, off the port bow! Percy leaped up in excitement.

"The shot-gun!" he cried. "They're signaling!"

Heading the boat toward the sound, he rowed his hardest, while Filippo strained forward, listening. Ten minutes dragged by, and once again—pouf!—slightly louder, and slightly to starboard. Percy corrected his course and again threw his whole heart into his rowing.

So it went for an hour, the signals sounding at ten-minute intervals, each louder and nearer than the one before. At last Percy thought it possible that their voices might be heard against the wind. He stopped rowing.

"Now shout, Filippo!"

Their cries pealed out together. They were heard. An answering hail came back. Soon the puff-puff-puff of the Barracouta's exhaust was driving rivets through the fog. A little later they were on board the sloop, answering the inquiries of Jim and Budge, while the empty pea-pod towed astern.

"Your seamanship wasn't bad, Perce," was Jim's judgment. "After you dropped the buoy, and then found you'd been rowing into the teeth of the wind, it might have been better to have tried only to hold your own until we came out to look you up. That breeze at first was nearer north than northeast, and when you ran before it you went south past the island. After that you were all at sea. But I might have done just the same thing. I can't tell you, though, how glad we are to see you back, even if it did cost next to our last shell of birdshot. The Gulf of Maine's a pretty homesick place to be kicking round in on a foggy night."

"You aren't any gladder than we are," replied Percy.

He glanced at the pea-pod towing astern.

"But say, Jim! Just cast your eye over that tub. When it comes to catching lobsters, haven't Filippo and I got the rest of the bunch beat to a frazzle?"