Soon after she knew.  A tall, handsome young fellow was bowing before Diana, who—­wonder of wonders!—­for an instant unclosed her great eyes and shot an electric glance into his smiling face.  The glance was brief as unexpected, yet it must have told the young man something, for he flushed and bowed again as if to hide his embarrassment.  It also told Louise something, and her heart, which had given a quick bound at sight of the man’s face, began to cry out against Diana Von Taer’s artifices.

“Mr. Arthur Weldon,” said the hostess, in her soft voice; and now, as the young man turned an eager gaze on Louise and half extended his hand, the girl’s face grew pale and she imitated Diana to the extent of dropping her eyes and bowing with frigid indifference.  Standing close he whispered “Louise!” in a pleading tone that made Diana frown wickedly.  But the girl was unresponsive and another instant forced him to turn to Beth.

“Why, Arthur! are you here, then?” said the girl, in a surprised but cordial tone.

“That is not astonishing, Miss Beth,” he replied.  “The puzzling fact is that you are here—­and under such auspices,” he added, in a lower tone.

Patsy now claimed him, with a frank greeting, and Arthur Weldon could do little more than press her hand when the line forced him to move on and give place to others.

But this especial young fellow occupied the minds of all four girls long after the crowd had swallowed him up.  Diana was uneasy and obviously disturbed by the discovery that he was known to the three cousins, as well as by the memory of his tone as he addressed Louise Merrick.  Louise, who had read Diana’s quick glance with the accuracy of an intuitionist, felt a sudden suspicion and dislike for Diana now dominating her.  Behind all this was a mystery, which shall be explained here because the reader deserves to be more enlightened than the characters themselves.

Arthur Weldon’s nature was a queer combination of weakness and strength.  He was physically brave but a moral coward.  The motherless son of a man wholly immersed in business, he had been much neglected in his youth and his unstable character was largely the result of this neglect.  On leaving college he refused a business career planned for him by his father, who cast him off with scornful indifference, and save for a slim temporary allowance promised to disinherit him.  It was during this period that Arthur met Louise and fell desperately in love with her.  The girl appeared to return the young fellow’s devotion, but shrewd, worldly Mrs. Merrick, discovering that the boy was practically disinherited and had no prospects whatever, forbade him the house.  Louise, until now but mildly interested in the young-man, resented her mother’s interference and refused to give him up.  She found ways to meet Arthur Weldon outside her home, so that the situation had become complicated and dangerous when Uncle John seized his three nieces and whisked them off to Europe.  Young Weldon, under an assumed name, followed and attached himself to the party; but John Merrick’s suspicions were presently aroused and on discovering the identity of the youth he forbade him or Louise to “make love” or even speak of such a thing during the remainder of the trip.