"Nonsense, child, never mind me! You look out of window and amuse yourself; we shall not be long, I guess," and in went Thorny, silently hoping that the dentist had been suddenly called away, or some person with an excruciating toothache would be waiting to take ether, and so give our young man an excuse for postponing his job.

But no; Dr. Mann was quite at leisure, and, full of smiling interest, awaited his victim, laying forth his unpleasant little tools with the exasperating alacrity of his kind. Glad to be released from any share in the operation, Betty retired to the back window to be as far away as possible, and for half an hour was so absorbed in her book that poor Thorny might have groaned dismally without disturbing her.

"Done now, directly; only a trifle of polishing off and a look round," said Dr. Mann, at last, and Thorny, with a yawn that nearly rent him asunder, called out:

"Thank goodness! Pack up, Bettykin."

"I'm all ready," and, shutting her book with a start, she slipped down from the easy-chair in a great hurry.

But "looking round" took time, and before the circuit of Thorny's mouth was satisfactorily made, Betty had become absorbed by a more interesting tale than even the immortal "Blue-beard." A noise of children's voices in the narrow alley-way behind the house attracted her attention; the long window opened directly on the yard, and the gate swung in the wind. Curious as Fatima, Betty went to look; but all she saw was a group of excited boys peeping between the bars of another gate further down.

"What's the matter?" she asked of two small girls, who stood close by her, longing but not daring to approach the scene of action.

"Boys chasing a great black cat, I believe," answered one child.

"Want to come and see?" added the other, politely extending the invitation to the stranger.

The thought of a cat in trouble would have nerved Betty to face a dozen boys, so she followed at once, meeting several lads hurrying away on some important errand, to judge from their anxious countenances.