"What's a knoll?" asked Tina.

"Oh, well... a knoll is like a mound... or a hill," answered Uncle Marvin.

"That's where we had our lunch!" exclaimed Tina. "The picnic area was a big mound of rock... a rocky knoll."

"I think you're right, again!" said Uncle Marvin. "You've nearly solved this mystery already!" They hurried back down the hill toward the picnic area.

Suddenly, Tina stopped. "Where's halfway? The giant turtle should be around here somewhere."

Uncle Marvin tried to think of a way to help. "Let's see... if I counted the number of paces from the rocky knoll to the crying stone, I could walk halfway by..."

"There it is!" Tina interrupted. She couldn't believe she had walked by it before without noticing. Alongside the path was a huge boulder, as big as a car. Actually, it was hard to tell how big it really was, since it appeared to be half buried. There were several smaller boulders arranged around it. "See... it looks like a giant turtle, and these rocks are its legs. And here is its head."

Tina put her head to the ground and peeked under the turtle's chin. "It's here!" she shrieked excitedly. Reaching into a narrow cranny beneath the stone that served as the turtle's head, Tina managed to extract a small plastic box. It looked like the ones her Mom used to keep leftovers in the refrigerator. Peeling back the lid, she found a plastic bag inside, containing a small notebook and a rubber stamp.

The rubber stamp, like the one Uncle Marvin's friend had made for Tina, was hand carved from an eraser. It had a picture of a turtle on it. "I think I have a green inkpad in my pack that will work nice for this one," said Uncle Marvin.