Early the next morning, Katie ran up the hill to the pond.
Dad and Joy were already working on the tree house steps.
"Morning, Dad," called Katie, climbing into the back of the truck.
She looked in the old bucket and pulled out the pulley. "What's this?"
"It's a pulley of course," said Joy.
"What's it for?" asked Katie.
"You'll see," Joy answered.
"Hey," said Katie.
"I can use this pole for my wind sock."
"What's a wind sock?" asked Joy.
"You'll see," answered Katie.
Pieces of the tin roof were spread on the grass.
Dad opened a can of dark blue paint.
"Here's a brush," he said to Joy.
"Do you want to help, Katie?"
"Nope," Katie said and jumped down from the truck.
"Mom and I are working on something. See you later."
Joy dipped her brush into the paint and carefully painted the first piece of tin.
"This roof has to look perfect,"
Joy said to herself as she turned to dip her brush again.
When she turned back, Magoo was sitting on the freshly painted tin.
"Magoo!" she said. "It's wet paint!"
Magoo got up and licked Joy's face, his blue tail wagging happily.
"Get out of here," cried Joy. "You'll spill the paint."
Magoo leaped back and sat down again.
"Good boy," said Joy.
Magoo watched Joy paint.
His eyes were fixed on the brush as it moved back and forth.
Then he reached out and touched the brush with his paw.
"Stop!" cried Joy.
"Do you want to be a blue Magoo?"
The dog pulled back his blue paw and gave Joy a sorry look.
By noon the steps were finished, the tin pieces were painted, and Dad was building the walls.
Joy and Magoo were lying in the grass.
They were both covered with paint: her shirt, his paws, her knees, his tail, her chin, his ear.
But Joy didn't care.
The tree house would be finished soon!
The next afternoon, Dad put in the door and the window.
Finally he nailed down the roof.
"It's done!" shouted Joy.
Katie, Mom, and Grandpa ran from the house to see.
Mom brought a flowerpot filled with daisies.
"Put it in the bucket, Mom!"
Joy shouted from the tree house.
The bucket was sitting on the ground with a rope tied to its handle.
The rope was attached to the pulley, which was attached to the roof.
Mom set the flowers in the bucket.
"Now watch this," called Joy.
She pulled on the rope, the pulley turned, and the bucket rose.
Joy lifted the daisies out of the bucket.
"Come on up, Mom!"
One by one everyone took a turn looking out on the Donovans' land from the tree house.
Everyone opened and shut the tree house door.
They looked out the window and tried out the pulley.
"Let's give a big cheer for Dad and Joy!" shouted Katie.
Mom, Grandpa, and Katie clapped and cheered.
Dad bowed. Joy beamed.
"One more thing," said Katie.
"Dad put up the new wind sock on the tree house roof.
Look! You can see it hanging from the pole."
Everyone looked up at the wind sock.
"Mom helped me make it."
"Wow!" said Joy.
"A wind sock tells us the strength and direction of the wind," explained Katie.
"When the wind is still, the wind sock just hangs."
"Like it's doing right now," said Grandpa.
"That's right," Katie said.
"But when the wind is strong, the wind sock flies straight out!"
Katie paused and opened her eyes extra wide.
"And if that wind is coming from the southwest, look out!
It might be tornado time!"
"That's pretty cool, Katie," said Joy. "Thanks!"