"I don't believe there is any flour on my shoes, any way," grumbled the culprit presently, stooping to examine his feet with the air of a guilty child. He thought he heard her laugh. "How much longer are you going to keep me in this infernal chair?" he fumed. "Bob!" called a voice from upstairs. "It's your aunt; she must have heard you come in." He sprang up only to come into collision with the dustpan full of flour which lay near his chair. A second more and the fruits of the sweeping drifted broadcast in a powdery cloud. "Delight! Dearest!" he cried, bending over the kneeling figure. "You must go upstairs and see your aunt--please!" she begged. "She will think it so strange." "All right, sweetheart. I'm coming, Aunt Tiny." When Willie entered a few moments later in search of his co-laborer, Delight was alone. He glanced questioningly about the room,--at the girl's flushed cheeks, the half-made cake, the snowy floor. "Bob--Mr. Morton spilled some flour," the young woman explained, evading his eye. The little old man made no response. He studied the burning face, the drooping lashes; he also looked meditatively at some footprints on the floor. They may not have been as startling in their significance as were the famous marks Crusoe discovered in the sand, but they were quite as illuminating. A trail of small ones led about the room and beside them, as if echoing to their light tread, was a series of larger ones. The inventor's gaze pursued them curiously to a spot before the stove where they became very much confused and afterward branched apart, the larger set trailing off toward the stairs, and the smaller moving back into the pantry. The detective stroked his chin for an interval. "U--m!" observed he thoughtfully. CHAPTER XIII A NEWCOMER ENTERS The next day Mr. Howard Snelling made his appearance at the Spence workshop. Bob was fitting wire netting to some metal uprights and struggling to focus his mind on what he was doing enough to forget that Delight Hathaway was on the other side of the partition when from the window above the bench he saw Cynthia Galbraith come rolling up to the gate in her runabout, accompanied by a strikingly handsome stranger. He hurried out to meet them. Her father and Roger, the girl said, had gone to a yacht race at Hyannis, so she had brought Mr. Snelling over. She introduced the two men but refused somewhat curtly to come in, explaining that she would be back, or some one else would, to fetch the guest home to Belleport for luncheon. Then, without a backward glance, she started the engine and disappeared around the curve of the Harbor Road.