A gay crowd of young people on bicycles passed by; it seemed unusually late to see so many out. As they wheeled off, talking in high spirits, there was naught, however, to distinguish them from a party of industrious young workers who had been kept indoors during the day, and whose youth demanded outdoor exercise, even if it had to be taken after dark.

“Where are their parents? still snoozing?” queried the Doctor,—“a ride after midnight may lead to a ‘skip by the light of the moon,’ but that’s none of my business,” and the bachelor doctor wended his way back towards his own domicile.

He was just about to enter when he spied a slight, agile figure, an elderly lady dressed in black, approaching and motioning to detain him. He could not mistake that light airy step, the nervous activity, the characteristic gestures. It must surely be she whose activity in good works he had known so long and well, yet he little expected to see her alone in the public street at that hour.

He ran down to meet her, took her arm under his and begged her to come in.

“I can’t, my dear, positively I can’t,” in a voice sweet and cheerful, as if she wished it but was too busy.

“Well, let me escort you home, then,” insisted the Doctor.

“No, my dear, not necessary at all, not a bit. I never have any difficulty at night. I wouldn’t take you on any account. I’ve been to the——” and she hesitated.

“Well, what can I do for you, Aunt Mary?”

She smiled as if the name was most welcome,—patted the Doctor on the back, called him one of “her boys,” and stopped a minute to chat.

But who was Aunt Mary?