"Take me outside, and I'll show you my best secret," Bronto told her.

"Tell me first," teased Catherine, tickling Bronto's tummy.

"Never!" giggled Bronto. "I'll only show you, but we MUST be outside first."

"I wanta see, too," cried Wild Sally. Soon word passed throughout the playroom and all the toys clamored to go. But Catherine did not want to haul bushels and bushels of toys up the stairs and out into the yard. So since Wild Sally had spoken first, she carried her and Bronto up.

"There," she said, setting Bronto in the grass beside the Japanese maple and Wild Sally on the birdbath. "Now, what's your secret?"

Bronto puffed out his cheeks as he blew-inward! He began to swell up bigger and bigger. He was as tall as Catherine, then as tall as a pony, then . . . poof! He disappeared altogether!

"Where are you? Did you pop?" cried Catherine, afraid she'd lost her pal forever.

"Are you dead?" squeaked Wild Sally.

"I'm right here." The whisper sounded as if it were coming from a huge, windy cavern, but she could not see Bronto anywhere.

"Where?" she whispered back.

"Heeeeerrrre!" A whisper half a block long swept by her. "I'm invisible because if anyone saw me being this big, they would get scared and maybe come after me with war planes. Scared people are dangerous."

"How big ARE you?" whispered Catherine.

"Speak up," came the windy whisper from way over her head. "I can't hear you from up here."

"Lean down," piped Wild Sally. Instead, Bronto carefully picked them both up in his huge, invisible front claws and gently lifted them higher than the roof of their house, high as the treetops before they came to rest on something solid that they could not see.

"Now we can talk more easily," said Bronto aloud, but still softly, as his voice was ever so much bigger and deeper than it used to be. They felt the vibration of that deep voice through their skin and knew they were sitting on his head.

"I know what let's do," Wild Sally cried out. "Let's go to Grandma Claire's and Grandpa Jim's farm!" If one has a full-size brontosaurus to ride on such a pleasant day in May, why not take a trip?

"I should have been a flying dragon," grumbled Bronto. But before Catherine could say yes or no, Bronto had stepped over the house and set off down Keith Avenue. He used his long, invisible tail to stop all the cars, so there were no collisions. Motorists had no idea why their cars could not go one minute, and then could go the next.

Catherine and Wild Sally were so high in the sky that no one thought to look up and see them. But every time Bronto came to a traffic signal on Highway 14, he had to duck his head. They felt like swallows, flat on their tummies, hanging on to Bronto's invisible, wrinkly skin with outstretched arms, swooping under the wires. People in cars could not believe their eyes. Maybe it was Supergirl, but she had no cape.

At the edge of Crystal Lake, Bronto left the highway and headed cross-country. "You know what?" mused Catherine. "Since you blew yourself full of air, why CAN'T you fly like a balloon?"

"Maybe I can," said Bronto in surprise. "I'm certainly not as heavy as I was in the old days. Look, the ground doesn't even sink down where I walk." Catherine and Wild Sally watched. Big patches of alfalfa bent over wherever the invisible feet were placed, but no footprints were left behind.

"Jump as high as you can," called Wild Sally, "and see what happens."

"Hang on!" And up they went as lightly as a hot air balloon. But the wind was from the southwest and that was the direction they wanted to go. Bronto grabbed a large cottonwood tree with his left hind claw to keep from drifting toward Lake Michigan.

"This won't get us to Kansas," sighed Catherine. That was when they heard the chopper. Catherine turned to see where it was and saw it heading straight for them. "It's going to cut poor Bronto to pieces!" she shouted over its noise.

"What about me?" Wild Sally was looking down at how far she would fall if Bronto were gone.

"You'll bounce," Catherine assured her.

The chopper noise got louder and louder. Bronto swung his head down to the level of the tree. But the helicopter did not pass over. It hovered just above and in front of Catherine and Wild Sally. They looked up and saw a woman pilot. She threw a ladder out the door and maneuvered the hovercraft so that the ladder moved right up to Catherine.

"I think she wants us to climb into the chopper," Catherine said.

"I can't," Bronto moaned. "I'm way way too big."

"We'll climb up and see what she wants," Catherine said. "You catch hold of the ladder."

"Roger," said Bronto. So while Bronto held one end of the ladder, Catherine and Wild Sally climbed into the cockpit.

The pilot looked a lot like Wild Sally. "My name is Sally," she said. "I saw you stretched out on your tummies in the sky with nothing under you. How do you do that?"

Catherine looked at Wild Sally. Could one explain to a grown-up about an invisible brontosaurus?

"Anyone who looks like me can't be ENTIRELY grown-up," Wild Sally whispered. "Go ahead and tell her."

Catherine studied Pilot Sally's face. "Have you ever seen a brontosaurus?"

Pilot Sally did not know why they were discussing prehistoric animals at a time like this, but she played along. "Only in pictures. They're the big ones, right? Eighty feet long and three stories high. And vegetarians. They didn't eat people. If there WERE any people then."

"They don't eat people," Catherine agreed. "There's an invisible brontosaurus hanging on to your ladder. Would you please tow him to Grandma and Grandpa's farm in Kansas?" She smiled sweetly, but her eyes had that impish Catherine twinkle.

"He's very light-weight," Catherine explained. "He blew himself full of air. But he can't float to Kansas against the wind. He's hanging on to that big tree with his hind foot now, but he'll let go if you fly southwest."

Pilot Sally laughed. That set Wild Sally off into more gales of giggles. "What did you say your name is?" asked Pilot Sally.

"Catherine Kay Waltz and this is Wild Sally and that is Bronto."

Pilot Sally opened the window and shouted, "Let go the tree, Big Guy, and let's go to Kansas!" Bronto released the cottonwood and floated happily behind the helicopter as it stopped hovering and whipped off toward the southwest.

But every time they flew over a herd of cattle or sheep, Bronto would sweep the tip of his long tail over one of their backs just to see them bolt and bellow or bleat in surprise. "Wonder why that one ram started running all of a sudden," Pilot Sally would say. Catherine had a pretty good idea, but she said nothing.

"There's Grandpa and Grandma's house," Catherine called out at last.

"I don't see any house," said Pilot Sally.

"That's how I know it's their house."

"You mean it's invisible, too?" Pilot Sally was circling now, in order not to fly by an invisible house somewhere.

Catherine pointed at two little stovepipes sticking up out of the prairie. See those? That's the roof. Now look, we can see the windows under the prairie. And there's the sun oven. Whoops! And there's the chickens swished up into the air by the tail of you-know-who!" She saw that the chickens all floated down safely, but they were pretty irate all the same.

"I get it; an underground house," said Pilot Sally, looking back at the row of windows facing the creek on the south side of the house. "Shall we set down over there on the hill by those two posts?"

"OK, but let me warn Bronto we're landing."

"I will! I will!" screamed Wild Sally, jumping around on the instrument panel until Pilot Sally swished her off. Wild Sally bounced off the floor so high, she went right out the window, but she caught the ladder and scrambled down to Bronto, shrilling, "We're landing! We're in Kansas!"

"I don't see any farm," said Bronto, looking over the rolling prairie. "Except chickens," he added with a grin. By then the 'copter had whish-whished down to the hilltop. The engine was shut off and the ladder fell to the ground. There was one more big whish as Bronto settled lightly into prairie grass with Wild Sally perched high on his
back. Catherine scrambled out of the 'copter and ran to check on her pals. BOING! She ran smack into a large, invisible head.

"Ow! My nose!" wailed Bronto. The roar was heard for miles. Fishermen on Marion Lake looked at the sky to see if a storm had come up. Dogs howled. Cattle looked up from grazing. Coyotes sniffed the air in alarm.

Catherine couldn't say anything. The impact had knocked the wind out of her, and she lay on her back gasping for breath. Wild Sally came sliding down Bronto's side crying, "Are you dead? Are you dead?" She landed on Catherine's ribs with a thump, pushing more air out of Catherine. Catherine swished her off. "Oh, you're alive; good," said Wild Sally.

By the time Catherine got her breath and Bronto's nose stopped smarting, Grandpa and Grandma had come to see why a helicopter had landed by their well. But first Grandma and then Grandpa tripped on an invisible tail and fell on their faces in the grass. Wild Sally ran over and peered into Grandpa's face and then into Grandma's. "Are you dead?" she asked each face.

"Catherine!" said Grandma in astonishment as she picked herself up.

"Catherine!" said Grandpa in equal astonishment as he picked himself up.

"Hi, Grandma Claire! Hi, Grandpa Jim!"

"What a wonderful surprise!" the grandparents said.

"I thought I'd drop in for a visit and bring my friends Pilot Sally, Wild Sally, and my invisible brontosaurus." Grandpa and Grandma each felt a huge, clawed, reptilian foot pat them gently on the head and heard a windy "Hi!" blow down from high above them. Then they saw great tufts of grass disappear and heard rather large teeth crunching.

"Be careful not to cut off any young trees while you're mowing the pasture," Grandpa called in the direction of the swath of disappearing bluestem.

"Okay."

After a snack of sun-oven bread with honey and goat milk eggnog, the two Sallys and Catherine waved good-bye and climbed into the helicopter. Catherine put her head out the window. "Grab the ladder," she called to Bronto.

"No, thanks," a far-away voice answered. "I'm floating back to Crystal Lake on this southwesterly wind." And he did. But it took a little longer.

Hours after Catherine and Wild Sally had landed on their roof and Mommy had come running at all the commotion and had helped them get off the roof, hours after telling their story to Mommy and Daddy and Becca and Baby Maria as they all enjoyed a good supper, hours after crawling at last into bed, exhausted from their adventure, they were awakened by a tapping at their window. Wild Sally leaped up and climbed on the headboard to peer out the window. No one could be seen. "Whozat?" she piped.

"Just me," a very sleepy Bronto whispered. "Open the screen so I can come in."

"You don't fit," Catherine reminded him. There was a drawn-out sound of air whooshing. A two-tone blue denim brontosaurus appeared on the windowsill.

"I do now," he said with a yawn. So Catherine opened the screen and Bronto jumped down to the bed, turned around three times and plopped down, already asleep.

The next day was Saturday and when everyone went out after breakfast dishes to work in the garden, they found a ten-foot high mound of finely chopped grass outside Catherine and Becca's window. Catherine figured out right away where it came from. She also knew that it was good mulch, and she worked hard hauling wagonloads from the pile to the strawberry bed and the rhubarb patch and the grape arbor and the tomato cages.
But what she could not understand was:

How did the grass get outside Bronto when he let his air out? No one knew. And why was the grass invisible while it was inside Bronto? And if the grass was invisible when it touched the inside of Bronto, why were people NOT invisible when they touched the outside of Bronto? No one knew.

But what EVERYONE knew was that the strawberries, rhubarb, grapes, and tomatoes were absolutely wonderful that summer. Catherine asked Bronto about this. He just smiled, patted his tummy, and said, "When there's magic inside, you just never know what will happen next."

He winked his left eye, then he winked his right, then threw back his head and gave a loud brontosaurus laugh. Catherine winked back and gave him a big hug.