he called to the girls. "And thank you, a thousand times!"

"Good-bye," Terry answered, while the others mumbled something.

They waited until he was out of sight, and then began the flood of "What do you think's" and "Maybe's." But of course they all agreed on one thing. That he was very charming and well mannered and that perhaps all foreigners were that way. But they decided it was indeed queer the way Dimitri's friends all came to them for advice on reaching the old houseboat. The newest caller gave rise to plenty of speculation, but the girls retired earlier than usual, and it was, perhaps, for this reason that Arden awoke sometime near morning, although it was still dark.

Deciding she could not get back to sleep, she lay tossing restlessly.

The events of the day marched before her now active mind. The gold snuffbox, Olga, Tania, Dimitri, the man who had come that evening. It was all very puzzling. She turned over and looked at Sim, sleeping peacefully. Nothing bothered her. Arden sighed and then started. What was that noise? Another mysterious visitor? She strained every nerve to listen. Then she smiled as she realized it was the motor of an auto purring along. Going to the window, she saw the stranger's car move slowly as it was started and disappear as it gathered speed. She looked at her wrist watch. The dial showed four-thirty, and he was just coming back from the houseboat!

"'Curiouser and curiouser,'" Arden said to herself as she climbed back to bed. "Alice in Wonderland had nothing on me. I wonder, too."

CHAPTER XII A Friend in the Deep

"Well, Sim," said Arden, stretching luxuriously, "I feel merry as a grig this morning."

"You don't say," Sim replied with sarcasm. "I guess you haven't looked outside then. I think we're in for a storm. What is a grig, anyway?"

"I don't know exactly," Arden continued, "but that's how I feel. It's very merry. How do you feel?"

"I feel like a chocolate nut sundae," Sim answered, making a wry face.

"You're a little cross, too. What's the trouble?" Arden asked.

"Oh, nothing. But I'm thinking, if we do get a northeaster, there won't be any bathing for days. I think I'll go in today just to get a swim before it comes," Sim answered. "Look at that," she continued, pointing to the little weather vane on the garage roof.

It was quivering in the wind and pointing due northeast. A brave morning sun was trying to pierce the leaden clouds, but not making much headway.

A week before, Arden had seen the second mysterious caller drive away in his car after tying up their boat. Since then they had neither seen nor heard from Dimitri, and in an orgy of swimming and sunbathing had almost forgotten about him, so perfect had the weather been and so completely had the girls enjoyed it.

Now Sim and Arden were in their room making plans for the day, and Terry, in gay bathrobe and slippers, strolled in to talk things over before breakfast.

"Don't go in today, Sim, there's bound to be a bad undertow; and besides, I have to go to town," Terry remarked as she had heard Sim's decision.

"But the tide will be coming in, and I'll only take a short dip. I'll be ready when you want to go. Let's eat now, and by the time we have our rooms in order I can go in for a swim. Then we'll drive to the village.

How's that?" Sim asked, smiling.

"You seem to have it all planned. I suppose it's all right. It's nearly ten now, so let's go down for breakfast," Terry suggested. "I'm hungry."

Sim and Arden, donning bathrobes and slipping their feet into soft mules, pattered downstairs after Terry.

They ate and put on their bathing suits when they went upstairs again, a habit they had fallen into since the lovely weather had begun.

When they went out a little later, Sim wished she hadn't been so insistent about swimming. The breakers were piling in, slapping down on the beach and churning up a white sudsy foam.

"I'm not going in _that_ sea," Arden decided, "and I don't think you should either, Sim."

"Nonsense, Arden," Sim said scornfully. "It looks a lot worse than it is."

"We'll have rain before night," Terry stated positively, "and the ocean is getting rougher all the time. Go on in, Sim, if you're going to, but be careful."

In a moment of bravado, Sim flung off her sweater and ran down to the water. She hesitated for a second as the cold water whirled around her feet, then, running swiftly, she plunged in head first. She was lost to sight immediately, but presently came up again and waved a hand to Arden and Terry, who were watching. Then she turned and began to swim out into the sea.

"I wish she wouldn't go out," Arden worried.

"Oh, she'll be all right. Sim's a good swimmer," Terry rea.s.sured her.

As they watched they could see Sim's scarlet bathing cap bobbing in the rough sea. She swam easily for a while and then floated on her back. Did they imagine it, or was she having trouble? Arden and Terry strained their eyes to see. Sim was swimming hard toward the sh.o.r.e but seemed to be making no headway.

"She's having a hard time getting back. Do you think she's all right?"

Arden asked anxiously.

"Wait-" Terry cautioned-"I'm not sure--"

Sim was still swimming but seemed to be tiring. She turned over on her back for a brief rest and began again. But it seemed no use. Apparently she was caught in a sea-puss and was still making no headway.

Terrified, Terry and Arden looked at each other, unable to utter a word.

In that instant a figure flashed by them and disappeared with a splash in the waves. Still speechless, they both knew--

It was Melissa!

She was going to help Sim to safety. The girls watching on the beach felt the relief so suddenly and so completely that each grasped the other.

"Melissa!" breathed Terry.

"She'll get her," answered Arden.

What little they had done to make friends with the girl came now in a rush of grateful memory.

Yes, Melissa would help them. She was their friend.

In almost no time at all Melissa and Sim walked out of the wild sea, a little further down the beach. Arden and Terry ran down to greet them.

"Sim, you idiot! I told you not to go in. Are you all right?" Arden asked breathlessly.

"Of course I'm all right," Sim panted.

"She was caught in a sea-puss. There's a trick in getting out. It's because the storm is coming and the inlet to the bay is so near," Melissa answered modestly.

"It was very brave of you to go out, just the same," Terry insisted. "It was just fine!"

Sim looked a little sheepish and pulled her sweater on over her dripping suit.

"Don't tell your mother, Terry; you know how she would worry," Sim said.

"Melissa, you were swell!" she exclaimed.

Melissa smiled happily. It was seldom, indeed, that her actions pleased anyone. Her whole day would be happy now, and at night she could lie in her hard little bed and remember how the girls had praised her. It took so little to brighten the dull life of Melissa.