"But it must be Herman Crocker," Penny argued. "We know Perry couldn't have committed the robbery."

"You say that you saw Herman in town?" Mr. Nichols inquired.

"Yes, he waited for Perry in the car and then drove away."

"Toward home?"

"Why, I didn't notice," Penny admitted.

"I did," Susan declared, eager to make a contribution. "He was driving the opposite way."

"Then there is a chance he may not have returned home yet," Mr. Nichols said. "I'm going down there and look around."

"May I go along, Dad?" Penny asked eagerly.

"You both may come," Mr. Nichols said after a slight hesitation, "but you must do exactly as I say."

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 k.n.o.b 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."

"Not necessarily," answered the detective. "House breaking is a different sort of crime entirely. The fact is, Herman Crocker doesn't impress me as being the kind of person who would commit such an act."

"The evidence is all against him," Penny argued.

"It is," Mr. Nichols agreed. "But one can't put too much faith in circ.u.mstantial proof. We must investigate first and draw our conclusions later."

The three were close to the Crocker premises by this time. There was no sign of the old man's car, and Mr. Nichols felt hopeful that he had not yet returned from town.

At the entrance of the lane, Mr. Nichols paused.

"Susan," he said, "I'd like to have you remain here. If you see Crocker's car coming up the road, run to the house as fast as you can and call out a warning."

"I'll keep a careful watch," Susan promised.

Mr. Nichols and Penny hurried on up the lane. They were quite certain that Mr. Crocker and his grandson had not returned from Kendon, but taking no chance, they pounded several times on the door.

"The place is empty all right," Mr. Nichols declared.

He tried the door and found it locked. Nor could they enter by either the side or rear entrance.

"How are we going to get in?" Penny asked in disappointment.

"One of the windows should be unlocked," Mr. Nichols said, looking up speculatively. "Here, I'll give you a boost."

He lifted Penny on his shoulders so that she could reach one of the high windows.

"Locked," she reported.

"All right, we'll try another," said the detective.

The second window likewise proved to be fastened, but when Penny tried the third one it opened.

"Good!" exclaimed Mr. Nichols. "Jump down inside and open the door!"

Penny found herself gazing into an untidy living room. The rug was moth eaten and there was dust everywhere on the old fashioned Victorian furniture. The walls were heavy with family pictures in wooden frames, and Penny's attention was drawn to a curious feather wreath.

"Hurry!" warned Mr. Nichols from below.

"I'll be there in a jiffy," Penny called back.

She jumped lightly down and ran to unfasten the door. Mr. Nichols entered and closed it behind him, turning the night lock.

"We'll have to work fast," he said crisply. "Old Herman may come back any minute."

"What do you expect to find?" asked Penny.

"Perhaps the necklace or at least some evidence which will attach Herman to the crime. I'll start searching in the upstairs bedrooms.

You might go through that desk."

With a nod of his head, the detective indicated an old fashioned secretary which stood in one corner of the living room.

The desk was filled to overflowing with papers of all sorts. A quick inspection satisfied Penny that the diamond necklace was not there, but if she had time she meant to examine the papers carefully.

"When you finish with the desk, start looking through the kitchen cupboards," Mr. Nichols called down from upstairs.

Penny was working swiftly at her task when the detective came down to a.s.sist her.

"There's nothing in the bedrooms," he reported. "I thought Old Herman might have hidden the jewels in one of the mattresses. Having any luck here?"