Everyone In the Valiant factory was excited. A machine stood on the factory floor, covered in wires and flashing lights. Pavlitski was running round it, jumping up and down shouting, "It's ready! My incredible time machine is finished!"

Myrtle came through the factory door. "What's going on? Why is everyone so excited?"

The Fat Boss saw her. "Hello Myrtle. Paviitski's finished his new invention. It's a time machine."

"A time machine, what's that?" Myrtle asked.

"If you press the buttons inside that box you will be taken back to a time gone by. Would you like to look?"

Myrtle nodded. Pavlitski opened the door. "After you," he said. As Myrtle was going through the door a giant bumble bee flew in through the window, and stung the Fat Boss on the bottom.

"Yeeeow!" he screamed. He shot forward and bumped into Pavlitski, who knocked Myrtle through the door. Myrtle flew into the time machine and crashed into a panel of buttons and switches. The door closed. Lights flashed and a strange sound filled the factory. "Oh help! My time machine!" Pavlitski yelled. "Oh help! My bottom!" the Fat Boss cried.

The time machine shuddered.

Inside the time machine Myrtle was spinning round. She had started it when she bumped the switches. The lights whirred around her like a giant Catherine Wheel. Then everything stopped. Myrtle lay on the floor until the dizziness went. "I'll have a word with Pavlitski, playing tricks on me like that," Myrtle said. She opened the door. "Pavlitski, just what do you mean by....?" She couldn't believe her eyes. The factory had disappeared. In its place was a forest, full of beautiful birds and unusual animals. Where the Fat Boss had been standing, there was a giant woolly mammoth. Myrtle shrieked. The mammoth ignored her and continued munching leaves.

"I must have gone back in time," Myrtle said. "Now that I'm here I might as well look round". A path led through the forest. Myrtle jumped on the grass and followed it, carefully avoiding the mammoth. The path led towards a river. There was a loud "CRASH!" followed by a cry. Myrtle stopped.

"Grrrh. Ugh ugh. No good. Bridge too short. Arrgh!"

She peeped through the leaves. A caveman was sitting in the water, next to a log.

"Oh...Hello. My name's Myrtle. Are you alright?"

"Grrr. Me alright. Can't make bridge right size."

Myrtle went to the bank. "Have you measured the width of the river?"

The caveman looked curious. "Grrr...Measure, what means 'measure'?"

"Well...You find out how many steps it is to the other side, and you make your bridge the same number of steps long."

"Hmmmm...Sound like good idea. How you find out how many steps?"

"I'll walk across the river bed, counting the steps as I go."

She entered the water and walked to the far bank carefully, counting the steps as she went. She reached the other side and shouted the number of steps to the caveman. She swam back and climbed out. "Now we can measure the bridge". She moved FORWARD the correct number of steps. "Build the bridge the same length as this line," she said. The caveman worked hard. He lowered the bridge across the river.

"Hooray! Bridge fits. Thank you Myrtle. My name Grub. Come back to my cave and meet wife, Splug. She hunt sabre tooth tiger today. Come and have cup of swamp water tea and tiger-burger."

"I'll be delighted," Myrtle replied.

ACTIVITY 1 : USE YOUR TURTLE TO FIND THE RIVER WIDTH.

Myrtle and Grub crossed the bridge, walked through the forest and climbed a steep hill. They stopped for a rest at the top. Myrtle looked at the countryside below. Grub pointed to a cave in the distance. "That where Grub and Splug live". He turned. "Over there is swamp with stinking horrid crocadiggle big teeths. Myrtle no swim, crocadiggle eat. Next is mammoth field, where woolly mammoth live. Ugh! What are flashing lights in forest?"

Myrtle looked. "Oh, that's the time machine."

"Slime Mash Mean?"

"No, 'time machine'. It brought me here."

"Me no like look of Slime Mash Mean creature. Slime Mash Mean might mash me. Let's go get tiger-burger."

They went down the hill to the cave. The burger and tea were delicious. As the sun was setting Myrtle decided to go back to the time machine. She said goodbye and walked over the hill and across the bridge. She liked Grub and Slug but wanted to get home.

ACTIVITY 2 : POINT YOUR TURTLE IN THE DIRECTION OF GRUB'S CAVE.

Myrtle climbed into the time machine. There were no labels on the switches. "Oh dear! I don't know which one to press. I'll hope for the best. Here goes." She pressed a switch, the lights flashed faster and things became wobbly again. After a few minutes the machine stopped and Myrtle opened the door. She screwed her eyes up. The sun was bright and it was hot. She jumped and landed on warm sand. There was sand all around. In the distance she saw a river. "I'll get a drink. I'm hot."

A terrible uproar came from the riverside. Men and women were shouting, pushing and splashing in the mud by the river. Some were drawing lines in the dirt and others were stamping the lines out. A man, covered in mud, rolled down a sand dune and stopped before Myrtle. He looked at her and fell to his knees.

"Oh Green Queen of the Bullrushes. I am your servant Ded-Loth. How can I serve your Holiness?"

"I'm Myrtle the Turtle. Where am I?"

"You're in the land of the Gods, by the holy river Nile; your Bullrushness."

"Ah, that explains all the sand," Myrtle said. "This must be Egypt. Why is everyone arguing and fighting in the mud?"

Ded-Loth bowed again. "It is the Inundation, my Green Scrumptiousness."

"What's the 'Inundation'?"

"Every year the Nile bursts its banks and floods the countryside. The waters go down and leave a layer of mud in which we plant our crops. The trouble is, every year the fences around our fields are washed away. We can never decide where one field ends and another starts your Myrtlessness."

"My name's Myrtle. Why don't you measure the fields and then next year you'll know exactly how big they are."

"But how do we measure the field your Turtlessness."

"I'll show you, and I'm a turtle not a Turtlessness."

Ded-Loth ran to the top of the hill and shouted, "All bow before the Great Green Queen Myrtlessness the Turtlessness."

Myrtle explained to the Egyptians how to measure round the outside of their fields. She drew a shape around each farmer's house.

"If you start and finish at the same place, you will have your own enclosed field around your house." She then helped mark out the boundaries for the new crops, moving and turning until she was back at the beginning.

ACTIVITY 3: USE YOUR TURTLE TO MARK OUT THE EDGE OF A FIELD.

When all the fields were drawn, Myrtle decided to visit the Pyramids before leaving. Myrtle followed the Nile to where she thought the Pyramids should be, but when she arrived she was disappointed. There was nothing there!

What has happened to the Pyramids? Will Myrtle find her way home?