around.
“Golly,” breathed Chris. “What a letter!” She read it a second time.
Ken read it a third time, but all he kept saying was “Wow,” until Mrs. Rockhill became curious. “Why are you holding that piece of paper over a lighted electric bulb?” she asked him.
“So we can read a secret message, Mom,” explained Ken.
“A secret message on a blank piece of paper?” Mrs. Rockhill was interested.
“Yes,” answered Chris. “You see, Marty used lemon juice instead of ink when he wrote this letter. The only way you can read it is over a lighted electric bulb. That’s what makes it a secret letter.”
Mrs. Rockhill smiled. “What will you children think of doing next? Is Marty having fun?”
“I’ll say he is,” replied Ken. “He went dinosaur hunting. Just think of that, Mom. Dinosaur hunting! Boy, that’s the life.” Then Ken added in a serious voice, “Er . . . Mr. and Mrs. Taylor are going to phone tonight. They want us to come there.”
Mrs. Rockhill frowned. “Don’t they know that Dad has already made plans for his vacation?” she asked.
“Oh, yes,” answered Chris. “We told Marty we were driving to the Pacific Coast because Dad likes to go deep-sea fishing there. Couldn’t we go to both places?” Chris pleaded with her big blue eyes. “Please, Mother?”
Mrs. Rockhill sadly shook her head. “I’m afraid it’s hard to change Dad when he makes up his mind to do something.”
“I know,” sighed Chris, “but not many children get the chance to go dinosaur hunting. Marty wants us to help look for a dinosaur graveyard, and it would make Grandma happy if we used the dinosaur tools she gave Ken and me at Christmas. This way they just sit in the closet.”
“That’s right,” agreed Ken. “What good are the tools if you don’t work with them?”
“We’ll see,” said Mrs. Rockhill as she turned back to reading her bird book. The twins decided she did not wish to talk any more about Dad’s vacation.
That evening at dinner, however, Ken and Chris tried very hard to persuade their father to go to Marty’s camp.
“It’s out of the question,” he replied. “Maybe next year you can look for dinosaur bones.”
Chris stopped eating and folded her hands in her lap. The food on her plate no longer tasted good.
Ken felt the same way, but he and his sister perked up when the phone rang a few moments later and Mrs. Rockhill spoke to Mrs. Taylor.
“How wonderful to hear your voice, Laura,” she said. “That bird book you recommended came in the mail today. It’s going to be very helpful.” There was a pause and then Mrs. Rockhill continued, “You say there are many different kinds of birds where you are. My, I’d give anything to see them.”
Chris looked at Ken and grinned. Mother seemed very interested and that was a good sign.
However, when Dad took the receiver and talked to Marty’s father, things did not appear very promising. “No, Sam,” he said, “we’re all set to drive to the Pacific Coast. We leave tomorrow morning at dawn. I’m sorry, but my heart is set on deep-sea fishing.”
The twins hung their heads in disappointment. Suddenly they heard their father say, “There is good fishing where you are? Hm. Sounds tempting, Sam. Yes, very tempting.”
Ken took a deep breath, and Chris crossed her fingers, hoping Dad would change his mind. He finally did, for the telephone conversation ended as he replied, “Okay, Sam. We’ll see you tomorrow. Save us a camp site.”
The twins hugged each other with joy.
“Just think of it, Ken!” exclaimed Chris. “We’re going dinosaur hunting.”
Her brother nodded, his cheeks flushed with excitement. “Boy, I can hardly wait to get to Marty’s camp.”
“Me too.” Then Chris shivered. She was thinking about the spooky noises Marty had mentioned in his secret letter. But she must not act like a scaredy cat, she told herself. After all, this was going to be a big adventure.
CHAPTER TWO
The Map
The Rockhill family left for Marty’s camp Saturday afternoon. Their station wagon rolled along the highway, with Dad at the wheel and Mother in the front seat next to him. The twins were sitting in the back, looking at their dinosaur tools—a small pick, chisel, shovel, and rock hammer.
“I wish I was going dinosaur hunting right now,” said Ken.
“So do I,” added Chris. “How far is it to Marty’s camp, Daddy?”
“Two hundred and fifty miles,” replied Mr. Rockhill.
“How long do you think it will take us to get there?” asked Ken.
“Oh, we should make it in two days.” Mr. Rock-hill tried to keep from smiling.
“Two days!” roared Ken. “Why a snail could travel faster than that.”
Mr. Rockhill laughed. “We’re averaging fifty miles an hour, Ken. So you tell me how long it will take us to get there.”
“It will . . . er . . .”
“Five hours if we don’t stop on the way,” finished Chris.
“Yes, five hours,” repeated Ken. Then, turning to his sister, he said in anger, “You didn’t have to tell me. I knew it all the time.”
“Of course you did,” said Mrs. Rockhill.
Ken grinned. He felt better.
In a little while he and his sister were getting restless.
“Could you please stop somewhere, Daddy? My seat aches,” said Chris.
“We will at the next rest area.”
Mr. Rockhill soon drove into a shady place near a stream, and everyone got out of the station wagon. The twins headed for the drinking fountain. They were still taking turns drinking when their parents returned to the station wagon a short while later.
“We’d better go, Ken,” said Chris.
“Okay,” he answered.
As soon as Ken and his sister had scrambled into their places the Rockhill family continued their journey. At seven o’clock that evening they were still driving.
Chris yawned and then said in a mournful voice, “All we do is ride, ride, ride. Of course we did
