At that moment Mrs. Masterbrook appeared in the doorway.
"Supper is ready," she announced.
"You'll have to keep it waiting," the detective told her. "I've just remembered an important engagement."
"I always serve at exactly six o'clock," Mrs. Masterbrook said primly. "The food won't be good if it stands."
"That doesn't matter to me," Mr. Nichols returned impatiently. "We'll hash up our own supper when we get back."
As he and the girls walked away, the housekeeper stood watching them with keen displeasure. Penny wondered if the woman guessed that they were going to the Herman Crocker place.
During the hike down Knob Hill, the girls told Mr. Nichols everything they had learned about Herman Crocker and his nephew, Walter. This time the detective did not term Penny's ideas wild. He listened in a manner which was most flattering.
"It's all a mix-up," Penny finished. "I feel sure that Mrs. Masterbrook is acquainted with Walter Crocker because she warned him to keep away from our cottage."
"Mrs. Masterbrook seems to have her finger in every pie," commented Mr. Nichols. "But I'm not much concerned with her affairs, or whether or not Old Herman has cheated his nephew. I'm only interested in learning if he is the one who stole the diamond necklace."
"If he'd rob his nephew it follows that he'd be the type to take jewels too."