Whatever had happened, one fact was plain, and that was that the smaller of the two cruisers was not swinging at anchor where they had left her. Nor could they see her anywhere. That she had dragged her anchor was impossible, since the harbour was almost land-locked and the night was still, with hardly enough breeze to stir the water. After the first few minutes of stunned surprise the twelve boys, gathered on the Adventurer, held council. It was Phil who eventually summed up the situation quietly and tersely as follows:

"The boat's gone. She isn't in the harbour, because if she were we could see her. Either she's been taken off as a joke or stolen. I can't imagine anyone doing it as a joke. In any case it's up to us to find her. We went ashore about eight, and it's now ten to eleven. It's probable that whoever swiped her waited until we were safely ashore and out of the way. I mean, they probably allowed us at least half an hour."

"They were probably watching us," suggested Steve.

"Why didn't they take this one instead of the other?" asked Cas Temple.

"Perhaps," replied Steve, "because they found the control locked. All they had to do on the Follow Me was break the padlock on the companion way doors. Still, that's just a guess. They may have preferred the Follow Me for some other reason."

"Never mind that," said Joe impatiently. "The question now is how we're to find her. Go ahead, Phil."

"I was going to suggest that we inquire among the other boats between here and the harbour entrance. Two or three still have lights aboard. Maybe they saw the Follow Me pass out."

"Somebody look after the tenders," said Steve briskly. "Haul ours out and tie the other astern. Give her a short line, so she won't switch around and fill with water. All ready, Joe?"

Five minutes later the Adventurer slid through the still water toward the mouth of the harbour. On her way she stopped twice to shout inquiries, and the second time a sleepy mariner, leaning, in pajamas across the rail of a small launch, supplied the information they sought.

"Yes, there was a cruising motor-boat went by about nine, or a little after, headed toward the Pier Head. I didn't notice her much, but she was painted dark. Come to think of it, it must have been pretty nearly half-past, for I remember hearing three bells strike just afterwards."

"You didn't see her after she went by here?" asked Steve.

"No, I was getting ready for bed and saw her through a port. Anything wrong?"

"Nothing," replied Steve dryly, "except that she belongs to us and someone's evidently stolen her. Thanks very much. Good night."

"Good night," was the answer. "I hope you get her."

"Well, we know she got this far," said Joe, "but--um--which way did they take her when they got outside?"

"That's the question," said Harry Corwin. "They might have gone across to Provincetown and around the Cape, or taken her up the shore or down. I guess the best thing for us to do would be to hike back and give the alarm. If we telegraphed--"

"She went north," said Phil with conviction.

"How do you know?" demanded Joe.

"I don't know, but think a minute. If you were stealing a boat you'd want to keep out of sight with her, wouldn't you?"

"Suppose I should."

"Then you wouldn't mess around in Cape Cod Bay. You'd set a course as far from other craft and harbours as you could. If they went south they'd be among boats right along, and they'd know that we'd work the wires and that folks would be on the lookout."

"Then where," began Steve.

"Let's look at the chart from here north," said Phil. The cover of the chart box was thrust back and the lamp lighted and as many as could do so clustered about it. Phil traced a finger across Massachusetts Bay past the tip of Cape Ann. "There's clear sailing for ninety miles or so, straight to Portland, unless--How much gas has she aboard, Harry?"

"Only about twelve gallons." It was Tom Corwin who answered. "We were going to fill again in the morning."

"How far can she go on that?"

"Not more than seventy at ordinary speed, I guess. She's hard on gas."

"Good! Then she'd have to put in at Gloucester or Newburyport or somewhere."

"Unless she ducked into Boston Harbour," said Steve. "I dare say she could tuck herself away somewhere there quite safely. A coat of white paint would change her looks completely."

"That's possible," agreed Phil, "but painting a boat of that size would take a couple of days, wouldn't it? It doesn't seem to me that they'd want to take the chance."

"Then your idea is that they're on their way to Portland?"

"Somewhere up there. They'd argue that we wouldn't be likely to look for them so far away."

"Well, here we are," said Steve. "We've got to go one way or another." The rougher water outside was making the Adventurer dip and roll. "As far as I can see, Phil's theory is as good as another, or maybe better. Shall we try going north, fellows?"

No one answered until, after a moment's silence, Perry remarked philosophically: "I don't believe we'll ever see her again, but we can't stop here, and we were going northward anyhow."

Murmurs of agreement came from the others. The only dissentient voice was Bert Alley's. "I don't see your argument," he said. "If I had swiped the Follow Me I'd hike out for New York or some place like that and run her into some little old hole until I could either change her looks or sell her."

"And be nabbed on the way," said Joe.

"Not if I stayed at sea."

"But you couldn't stay at sea if you had only twelve gallons of gasoline aboard. Wherever she's going, she will have to put in for gas before long." Phil stared thoughtfully at the chart. "I'll allow," he went on, "that she may have gone any other direction but north. For that matter, she may be anchored just around the corner somewhere. It's all more or less guesswork. But, looking at the probabilities, and they're all we've got to work on, I think north is the likeliest trail for us to take."

"Right-o," said Steve, turning the wheel and pointing the boat's slim bow toward Gurnet Point, "We've got to take a chance, fellows, and this looks like the best. In the morning we'll get busy with the telegraph and tell our troubles, but just now the best we can do is keep a sharp lookout and try to think we're on the right course. I'm going to speed her up, Joe, so you might dab some more oil and grease around your old engine."

"All right. You fellows will have to clear out of here, though, while I get this hatch up. Some of you might go forward and keep your eyes peeled. I don't suppose, however," he added as he pulled the engine hatch up, "that they'll show any lights on her."

"Not likely to," agreed Harry Corwin. "They'll run dark, probably, until they get near a harbour. Look for anything like a boat, fellows. It's a mighty good thing we've got this moonlight."

"Yes, and we'll have to make hay while the moon shines," added Wink Wheeler as he climbed out of Joe's way, "for it won't last much longer. It'll be as dark as pitch by one or two o'clock, I guess."

"Well, we've got a searchlight," said Perry.

"There's no need for more than three of us to stay up," said Steve. "I'll keep the wheel and Joe will stay here with me. Phil, you take the watch for a couple of hours and then wake someone else."

"Huh!" said Perry. "I'm not going to bed! Who wants to sleep, anyway?"

Apparently no one did, for although presently the dozen fellows were distributed over the boat, not one went below. Phil and Han stretched themselves out at the bow, Steve, Joe, Harry and Tom Corwin and Cas Temple remained on the bridge deck and the rest of the company retired to the cockpit, from where, by looking along the after cabin roof, they had a satisfactory view of the course. Perhaps one or two of the boys did nod a little during the next two hours, but real slumber was far from the minds of any of them. The Adventurer was doing a good twenty miles an hour, the propeller lashing the water into a long foaming path that melted astern in the moonlight. Ossie busied himself in the galley about midnight and served hot coffee and bread-and-butter sandwiches. Only once was the Adventurer changed from her course, which Steve had laid for Gloucester, and then the light which had aroused their suspicions was soon seen to belong to a coasting schooner beating her way toward Boston. Of small boats there were none until, at about one o'clock, when the two white lights of Baker's Island lay west by north and the red flash on Eastern Point showed almost dead ahead, Phil called from the bow.

"Steve, there's something ahead that looks like a boat or a rock. Can you see it?"

"Which side?"

"A little to the left. Port, isn't it? Han doesn't see it, but--"

"I've got it," answered Steve. After a moment he added with conviction: "It's a boat. Has she changed her position, Phil?"

"Not while I've been watching. Looks as if she was going about the same way we are." The others came clustering forward from the stern to stare across the water at the dark spot ahead which, in the uncertain light of the setting moon, might be almost anything. If it was a boat, it showed no light. Anxiously the boys watched, and after a few minutes Steve announced with quiet triumph:

"We're pulling up on her, fellows, whoever she is!"

"She's the Follow Me," declared Harry Corwin. "She must be, or she wouldn't be running without lights."

"We'll know before long," said Steve. "I wish the moon would stay out a little longer, though. Joe, try the searchlight and see if you can pick her up."

But the craft ahead was a good mile away and the Adventurer's small searchlight was not powerful enough to bridge that distance with its white glare. "They're making for the harbour, anyway," said Harry Corwin, "and so she can't get away from us if we lose her now." Even as he ended the last pallid rays of the moon vanished and they found themselves in darkness save for the wan radiance of the stars. Lights unnoticed before sprang up in the gloom along the shore and a dim radiance in the sky showed where the town of Gloucester slumbered.

"If they double on us now we'll lose them," muttered Steve. "Put that light out, Joe. We can see better without it."

"How far off is the harbour?" asked Harry.

"About two miles. You can hear the whistle buoy. That white light to the left of the red flash is the beacon on the end of the breakwater." He moved the helm a trifle and examined the chart. "There are no rocks, anyway, and that's a comfort. I can't say I like this running at night. How far away was she when the moon went back on us, Harry?"

"Oh, three-quarters, at a rough guess."

"Nearer a mile and a quarter, I'd say. Well, if she doesn't dodge along shore we'll have her in the harbour. Always supposing, that is, that she really is the Follow Me."

"She can't be anything else," answered Harry. "No sensible skipper would go ploughing around at night without a light. Hello! Isn't that a light there now?"

"Where? Yes, you're right! She's lighted up at last! Afraid to go in without lights, I dare say, for fear of arousing suspicion. I'm getting to believe she is the Follow Me, Harry."

"I haven't doubted it once. Do you suppose she knows we're after her?"

"She knows we're here, of course, but she can't be certain we're after her. Still, turning that searchlight on was a sort of give-away. If she really does go inside it's just because she's afraid of her fuel giving out. We'd better anchor as far out as we can and keep our eyes open until daylight comes."

"She couldn't get gas before morning, I guess," said Joe. "Looks to me as if, if she is the Follow Me, they've run themselves into a trap!"

"Hope so, I'm sure," said Wink Wheeler. "If we've caught her we've certainly been lucky, fellows!"

"Don't count your chickens until they're hatched," advised Ossie. "Maybe she isn't the Follow Me at all."

"I can't see her light now," called Phil from the bow. "Hold on, there's a green light, I think! No, I guess I was wrong. Can't see anything now, Steve. Can you?"

"No, she's turned and run inside back of the breakwater. Keep your ears and eyes open for that whistling buoy, Phil. I want to pass it to port."

"It's pretty near. There it is now! Look!"

"I've got it! All right. Now it's straight for the white beacon." Steve sighed relievedly. "No use hurrying any longer, I guess." He eased the throttle back and the Adventurer slowed her pace. "Have a look at the chart, Harry. Isn't there a buoy near the end of the breakwater?"

"Yes, a red spar buoy."

"What's the depth just inside?"

"Four fathoms, shoaling to one."

"Good enough. We'll drop anchor just around the breakwater and train the searchlight across the channel. I don't believe, though, they intend to run out again before morning. All I'm afraid of is that they swung off when darkness came and are sneaking around the Cape."

"I'll bet anything we'll find her at anchor when daylight comes," replied Harry. "She had only enough gas for seventy miles, and she's gone about sixty at top speed. We've got her, Steve. Don't you worry."

"Hope so. Get your bow anchor ready, Han, and stand by to heave. When you let go make as little noise as you can. I'm going to turn the lights out, fellows, so don't go messing about or you may walk overboard. Switch them all off below, Ossie, will you? If those chaps have anchored just inside the breakwater there's no sense in letting them know that this is the Adventurer. Got your anchor ready, Han?"

"Ay, ay, sir!"

"All right. Don't let your windlass rattle. Keep quiet, fellows." Suddenly all the lights on deck save that in the binnacle went out, leaving the boat in darkness. Nearby the red flash of the lighthouse glowed periodically, while, ahead, shone the white beacon. In silence the Adventurer drew nearer and nearer to the latter, put it abeam and then swung to starboard. "Let her go, Han," called Steve softly. Those on the bridge deck heard the faint splash of the hundred-pound navy anchor as it struck the water. Han crept back and swung himself down to the bridge.

"All fast, sir," he reported.

Somewhere in the darkness at the head of the harbour, where tiny pin-pricks of light twinkled, a town clock struck two.