"Is that because the sun's gone down?"

"I think so," said Brad "It's my guess that wherever this thing came from, it was a lot hotter than here. I also think it must be reliant on some other life-form for its initial start, because it had to wait until something removed the top part, the bit you unscrewed. That was you, remember?"

'"Oh yes," said Turran remembering "I started it off!"

"Lucky you," said Brad without smiling "Come on, we'll get back to the vehicle, and I think I'll park a bit further away. We can take turns to get some sleep. You have the first four hours, OK?"

"Oh Dad, do I have to?"

"You sure do. If you don't get some sleep, you'll be worn to a frazzle by tomorrow!"

The third day dawned hot and clear. Turran woke with a start. He had half a nightmare left in his head as he sat up and pulled the canvas flap aside. His father was standing some distance away, taking photographs.

Then Turran saw the thing. It was enormous! It had sprouted long, straight rods, which stuck out in all directions and impaled themselves into the ground, and from its centre, a large, petal-like mass had opened outwards.

Turran jumped from the back of the vehicle and ran over to where his father was standing.

"I was wrong," said Brad, "It wasn't sleeping."

"Wow!" said Turran, "Look at this thing!"

"Amazing, isn't it!" Brad agreed "It has doubled in mass at least three times since yesterday, and by my calculations it has increased its surface area at least a thousand times. I've calculated the dimensions we can expect it to reach over the next five hours, if it continues at its present growth rate. We'll, er, have to shift the Rover again – just for safety you understand?"

"How big do you think it will be when it's finished growing?" asked Turran."

"I'm afraid I have no idea," said Brad "But there is one good thing about it ..."

"What's that?"

"It isn't based on the animal model as far as growth is concerned. It's nearer to vegetable, which puts it