They followed him guardedly. "Tania, come here," he ordered sternly. The big white-and-tan dog stood like a statue. "Come here!" her master repeated. Tania walked toward him with queenly dignity.

Dimitri then put his hand on Arden's arm. "These are my friends," he said; and then to the girls: "I will tell her that in Russian, and she will be sure to understand. Then if you will each pat her head, you will be fast friends." He smiled enthusiastically.

The little ceremony of introduction was carried out, and Tania ceased her worried barking. The dog put a dainty paw on Arden's white shorts as if to rea.s.sure them all most completely.

"Such a lovely dog," murmured Sim.

"And intelligent, too," added Terry.

"I will have pleasure in showing you my little floating home here, if you would like to see it," said Mr. Uzlov, smiling his invitation. "It is the first time I have ever lived on a houseboat. They are rather strange creatures, is it not so?" Again he smiled.

"This one is very old," Terry said. "I don't know how many years it has been here. It belongs to Mr. Reilly, the town chief of police. This is the first time it's been rented in I don't know how long. I think you hadn't better try to move it either by sail or an outboard motor," she warned with a laugh. "I fancy it would leak like a sieve."

"Doubtless," he agreed, also laughing. "But I shall be safe enough on my boat. I don't intend to move her, and probably she rests on the muddy bottom of this bay and marshy land."

The houseboat was not large. It consisted of a sort of large shed, with windows, doors, and a flat roof perched on what had once been a scow.

There was a narrow s.p.a.ce running all around the house part, between it and a low rail. There was a small float at one end to which a rowboat was made fast. From the float a cleated plank gave access to the lower deck of the boat, if a deck it could be called. There was also a short flight of rather rickety steps at the stern by which the girls had come aboard.

The houseboat had once been painted green, but little of the original color remained.

"Will you follow me?" Dimitri Uzlov requested, opening a sagging door which led into the rear part of the houseboat. "This is where I do my work."

The girls saw that the interior of the craft consisted of really but one large room, divided by heavy hanging curtains into two apartments. The one they had entered did the double duty of a sleeping and working s.p.a.ce, for there was a cot in one corner. On a table gleamed a bright bra.s.s samovar with some dishes about it. There was an easel and on a chair near it brushes in pots, tubes of paint, and a much-smeared palette. The curtained-off part was the kitchen.

"I am finishing a marine for a client," the artist said, indicating the half-finished canvas on the easel.

Arden and her chums noticed several canvases stacked together near one wall, and standing beside a window was another easel with a picture on it. But what the subject of this picture was could not be seen, for it was covered with a sheet.

"Oh, how lovely it is here!" Arden exclaimed. "To have a place all your own to do just as you please in and no need to worry about neighbors looking in your windows!"

"At least I am sufficiently isolated here," the Russian agreed. "The houseboat is hard to come at. I always loved marshlands. That is one reason I was attracted to this boat, old and shabby as it is."

"It's wonderful, I think," murmured Sim.

"But a little lonesome," suggested Terry.

"I came here for lonesomeness-as one reason," Mr. Uzlov said.

Arden glanced at the exposed picture showing a stormy ocean with sea gulls fighting the wind. Dimitri smiled understanding as she said:

"It is lovely!"

The artist seemed to be losing some of his reluctance.

Arden walked over toward the other painting-the one covered with a sheet.

She wondered what it could be.

"What is this?" she asked, extending a hand as though to lift the covering. "Is it your masterpiece?"

Instantly the young man's face clouded.

"Please-that-do not touch it-please! It is-unfinished. I cannot show it to you. I am sorry!"

His first words had been hurried-stiff-exclamatory. The girls at once sensed a change in his manner. But his last word had been almost pleading. Even then it seemed as if his friendliness, which had been so p.r.o.nounced on the arrival of his visitors, was now as covered as was the picture.

Arden drew back as if hurt.

"I didn't mean to be curious," she faltered. "I'm sorry!" Even her words sounded empty of meaning.

Another change came over the face of Dimitri Uzlov.

"You will be so good as to pardon me for my seeming ill haste," he murmured. "But that picture-no-it must not be seen-yet."

Matters were becoming a little strained and awkward, but Terry went into the breach cleverly by saying:

"We had better be going. It must be nearly lunch time. Mother will be expecting us. Thank you for your help, Mr. Uzlov, and for letting us see your houseboat."

He did not try to stop them, nor did he express regret at their sudden departure, but simply said good-bye and then watched them pull away in the waiting rowboat.

"Queerest person I ever met," Terry began. "One minute all sunshine and gladness, and the next, all worked up because Arden asked about his old picture."

"I wouldn't have touched it, anyway," Arden replied. "I was just trying to show a little interest. My goodness! Who would want to live in such a messy place? No one but the sort they call-artists!"

"I wonder what the hidden picture was?" Sim asked curiously. "Perhaps he's a spy, making maps of the coast and inlet."

"Now who said they refused to get mixed up in another mystery?" Terry jeered. "Well, let's go home, I'm hungry."

"So am I, but I would like to know what was on that easel," Sim remarked as Terry pulled with strong strokes back to "Buckingham Palace."

CHAPTER IV A Girl and a Bracelet

By afternoon the sun was warmer, and the girls, dressed in bathing suits, were lying on the caressing sand of the little beach not far from the house. They had spread their beach coats out beneath them and were sprawled in favorable att.i.tudes to acquire the all-important tan. At intervals one of the girls sat up and coated herself liberally with cocoanut oil. They did not seem to feel exactly like talking, as the sun made them deliciously lazy. Perhaps they were thinking of their adventure at school when, as told in the first volume of this series, _The Orchard Secret_, many surprising things happened. Or they may have been letting their minds wander to more surprising occurrences, as told in the _Mystery of Jockey Hollow_.

Sim, Arden, and Terry had been chums and schoolmates ever since they first began to acquire knowledge in Vincent Prep, and their friendship and loyalty continued until the present time, when they were just finishing their freshman year at Cedar Ridge, the well-known college for girls at Morrisville. This small city was not very distant from Pentville, where the three lived.

As Sim sat up to apply the oil again, she saw a dark object bobbing up and down far out on the ocean.

"Look, girls," she cried, "does that look like someone to you, or is it just a log?"

"Where?" Arden asked, squinting at the bright water toward which Sim pointed, and then they were left in no doubt, for the bobbing dark spot began to swim. With long, sure strokes it came nearer to them, and they could see the white foam where the thrashing feet churned it up in perfect timing.

"Some swimmer," Sim said admiringly. "Wonderful form. I wonder who it is?"

"We'll soon see," Arden replied, and Terry nodded in agreement.

The figure was making rapid time, and as it neared the beach, waited for just the right minute and then coasted in on a blue-and-white breaker.