"Maybe so," Mr. b.u.t.terworth grinned. "My lips, they are sealed."

"Sealed?"

"I promise Mrs. Marborough I tell nothing of what I see in the house."

"Then there is something mysterious going on there!" Penny exclaimed.

"Tell me, why did you go to the house?"

"Mrs. Marborough sent for me."

"But why?" Penny demanded, exasperated because she could learn nothing of importance. "Did Mrs. Marborough sell you something?"

"Maybe so, maybe not," the second-hand man answered, climbing into his overloaded car. "You ask her."

Penny watched him drive away, and then returned to her own doorstep. She was listlessly throwing acorns at a squirrel when Louise Sidell came down the street, dressed in her Sunday best.

"What's the matter, Penny?" she inquired, roving over to the porch. "How do you feel this morning?"

"Lower than the center of the earth. I've lost my reputation with Dad, my allowance, and my initiative. If I had a nickel I'd go drown myself in a c.o.ke!"

"What you need is a nice adventure," Louise said mischievously. "How about a trip out to Mrs. Marborough's tomorrow night?"

"I've had enough of wells!"

"Penny, you don't mean it!" Louise grinned. "After discovering those loose bricks, you'll just forget about them?"

"Why not?" Penny demanded wildly. "Dad won't let me leave the house at night any more without a six thousand page report on where I am going. If I so much as mention Mrs. Marborough's well, he'll clap on a double punishment."

"You can manage it somehow," Louise declared with confidence. "I'll meet you tomorrow night about eight-thirty."

"Maybe," Penny said gloomily.

Throughout the day she tried to win favor with both Mrs. Weems and her father by doing small things to please them. When the housekeeper came home from church, dinner awaited her. Penny insisted upon doing the dishes. She straightened the kitchen, she brought her father his bedroom slippers, and refrained from turning on the radio while he was reading.

The schedule was a trying one for her, but she kept it up faithfully all day Sunday and until after dinner on Monday. Then came the denouement upon which she pinned her hopes.

"Dad," she said demurely, leaning on the chair arm and stroking his hair, "with your kind permission I should like to absent myself from the house for a few minutes."

"Where do you plan to go?" he asked, trying to act stern.

Penny was prepared for the question. From her pocket she whisked a lengthy typewritten paper, handsomely decorated with a diagram.

"What's this?" Mr. Parker asked, his lips twitching slightly.

"Merely a report on my proposed movements for the next hour. At eight-thirty I hope to be at Louise's house. Eight thirty-four should find me on Adams Street, moving southward. At eight thirty-eight I pa.s.s Gulbert Park--"

"Never mind," Mr. Parker interrupted. "I see by this lengthy doc.u.ment that your ultimate destination is Mrs. Marborough's estate. Isn't it rather late to pay a social call?"

"Eight-thirty?"

"What does this X on the map represent?" the publisher asked, his interest shifting.

"Oh that?" smiled Penny. "Merely one of the fixtures in Mrs. Marborough's yard. Louise and I think treasure may be hidden there."

Amused by what he took to be his daughter's whimsy, Mr. Parker returned the diagram to her.

"Do I have your permission to leave the house?" she asked anxiously.

"Yes, you may go," he agreed. "But mind, no late hours. And no more tall tales about falling into wells!"

Louise was waiting for Penny in the Sidell yard and the girls went as quickly as they could to the Marborough estate. The house was completely dark, leading them to believe that the widow might have absented herself for the evening.

"We'll have to be especially careful," Louise warned as they approached the old wishing well. "She might return at any moment and find us."

Penny had brought the silken ladder, extra rope, a flashlight and a suit of warm coveralls which her father used when he worked on the car.

Donning the bulky garment, she prepared to descend a few feet into the well.

"Do be careful," Louise said anxiously. "If you should fall you might kill yourself."

"You think of the most cheerful things," Penny muttered, climbing nimbly down the swaying ladder. "I'm not taking any chances though. I'll tie myself to the ladder with this extra piece of rope."

After she had gained the position she desired, Louise handed down the flashlight. Penny carefully inspected the brick wall.

"I believe it is an opening!" she reported jubilantly. "I really do.

Here, take this flash. I can't work and hold it."

While Louise directed the beam from above, Penny tugged at the bricks.

Unable to move them, she called for a tool which she had brought with her. By means of it, she easily pried one of the bricks loose. Pushing her arm through the opening, she encountered only empty s.p.a.ce.

"It's a little tunnel I think!" she shouted to Louise. "Take this brick, and I'll try to pry out others!"

Within ten minutes Penny had handed up enough of them to make a large pile beside the flagstones.

"Do you realize you're practically destroying Mrs. Marborough's well!"

Louise said uneasily. "How will we ever explain this?"

"I can put the bricks back again," Penny a.s.sured her. "They were meant to come out. Now, the flashlight again."

Balancing herself precariously on the ladder, she directed the light through the opening she had created. A long narrow tunnel which she judged to be about five feet below the ground, extended as far as she could see.

"I'm going to try to get in there!" she called to Louise. "Toss me a life preserver if I fail!"

Calculating the s.p.a.ce, Penny swung her feet from the ladder to the ledge.

Retaining an arm hold on the ropes, she edged herself backwards into the hole.

"It's much easier than it looks," she called encouragingly to her chum.

"Come on, if you want to explore."

Louise hesitated, and then daringly climbed down into the well. Penny helped her from the ladder into the tunnel.