On their arrival at Santa Monica Mr. Merrick invited the party to be his guests at luncheon, which was served in a cosy restaurant overlooking the ocean.  And then, although at this season it was bleak winter back East, all but Uncle John and Aunt Jane took a bath in the surf of the blue Pacific, mingling with hundreds of other bathers who were enjoying the sport.

Mrs. Montrose and Uncle John sat on the sands to watch the merry scene, while the young people swam and splashed about, and they seemed—­as Miss Patsy slyly observed—­to “get on very well together.”

“And that is very creditable to your aunt,” she observed to Maud Stanton, who was beside her in the water, “for Uncle John is rather shy in the society of ladies and they find him hard to entertain.”

“He seems like a dear old gentleman,” said Maud.

“He is, indeed, the dearest in all the world.  And, if he likes your Aunt Jane, that is evidence that she is all right, too; for Uncle John’s intuition never fails him in the selection of friends.  He—­”

“Dear me!” cried Maud; “there’s someone in trouble, I’m sure.”

She was looking out across the waves, which were fairly high to-day, and Patsy saw her lean forward and strike out to sea with strokes of remarkable swiftness.  Bathers were scattered thickly along the coast, but only a few had ventured far out beyond the life-lines, so Patsy naturally sought an explanation by gazing at those farthest out.  At first she was puzzled, for all the venturesome seemed to be swimming strongly and composedly; but presently a dark form showed on the crest of a wave—­a struggling form that tossed up its arms despairingly and then disappeared.

She looked for Maud Stanton and saw her swimming straight out, but still a long way from the person in distress.  Then Patsy, always quick-witted in emergencies, made a dash for the shore where a small boat was drawn up on the beach.

“Come, Arthur, quick!” she cried to the young man, who was calmly wading near the beach, and he caught the note of terror in her voice and hastened to help push the little craft into the water.

“Jump in!” she panted, “and row as hard as you ever rowed in all your life.”

Young Weldon was prompt to obey.  He asked no useless questions but, realizing that someone was in danger, he pulled a strong, steady oar and let Patsy steer the boat.

The laughter and merry shouts of the bathers, who were all unaware that a tragedy was developing close at hand, rang in the girl’s ears as she peered eagerly ahead for a sign to guide her.  Now she espied Maud Stanton, far out beyond the others, circling around and diving into this wave or that as it passed her.

“Whoever it was,” she muttered, half aloud, “is surely done for by this time.  Hurry, Arthur!  I’m afraid Maud has exhausted all her strength.”

But just then Maud dived again and when she reappeared was holding fast to something dark and inanimate.  A moment later the boat swept to her side and she said: