The assignment was to write about an agricultural show. I got a mad picture in my mind that the animals would actually put on a show rather than just standing there for the people to look at them. And that raised the interesting possibility of training the animals to do something amazing. Such as a cow walking a tightrope for example. I'm not sure this story works, but I do still like the central idea...

It was late in the afternoon on a hot spring day. David and Nathan were in the paddock trying to teach the cows to walk on a tightrope. The rope swayed gently some three feet above the paddock. Each end of it was firmly attached to a ramp. All the cows had to do was walk up a ramp, amble across the rope to the other side and then go down the other ramp back to the paddock. What could be simpler? But the cows seemed to be finding it very difficult and David was starting to have second thoughts about what he was trying to achieve.

At her umpteenth attempt, Daisy the Frisian cow fell off the tightrope when she was half way across. She landed on top of Buttercup the Hereford cow who had been watching Daisy’s progress with interest. Annoyed, Buttercup gave a loud moo of disgust and butted Daisy in the ribs. Daisy hung her head in shame and looked embarrassed. She had failed again, just like she seemed to fail every time she tried to walk across the tightrope. "We’ve only got a week before the Agricultural Show," said David in despair. "If we can’t get these cows trained up soon we may as well cancel our spot because we’ll have nothing to display."

"I know," agreed Nathan. "What’s so hard about walking in a straight line? That’s all they’ve got to do. Just because the line is very narrow and three feet up in the air shouldn’t really make any difference. But the stupid animals just won’t do it. They keep wandering away to the left or the right and then they fall off. It’s very frustrating."

"Peter Hargreaves is probably laughing his socks off at us," said David. "His sheep juggling will win best of show again. You mark my words."

"I’ve never seen his act," said Nathan. "I’ve always been too involved in preparing for my own. How does he get sheep to juggle? That’s pretty impressive!"

"He doesn’t," said David. "Sheep can’t juggle. They are far too dumb to do anything as clever as that. Peter just comes on stage with three sheep clutched in his hands. Then he bows to the audience and starts to juggle the sheep. The audience love it. The sheep make really funny bleating noises as he tosses them around. Sometimes he fails to catch one on its way down. The thump and squeal as the sheep hits the ground is absolutely hilarious. I’ll swear that sometimes he misses the catch deliberately just to give the audience a laugh!"

"I see," said Nathan. "But he might have some serious competition this year. Someone in the pub told me that Nicola Green has been teaching her old dogs some new tricks. She’s putting a magic show together. She’s going to get the dogs to tear a duck in half. One dog takes the head, one dog takes the tail and then they both pull very hard."

"That should be worth watching," said David, brightening up a bit. "Since it’s a magic show, I presume she gets the dogs to put the duck back together again at the end?"

"The dogs haven’t quite got the hang of that bit yet," said Nathan. "And as a result, the pond at the bottom of her garden is rather too full of fractional ducks at the moment."

And that’s when the Martian spaceship swooped in silently and landed in the far corner of the paddock. David, Nathan and the cows watched it with open mouthed amazement.

It was coloured forty shades of green and it blended in easily with the grass that covered the paddock. If David and Nathan hadn’t actually seen it coming in to land they would never have even noticed that it was there, so perfect was its camouflage.

Presently a hatch opened in the side of the ship and a ramp slid out. Six blue Martian cows walked down the ramp and started to crop the grass. They seemed to be perfectly at home despite their odd colouring.

A Martian cow herder followed the cows down the ramp. He seemed rather taken aback when he noticed David and Nathan staring at him. "Sorry," he said. "I didn’t know there was anybody here otherwise I wouldn’t have landed. I just dropped in to fill the cows up. Your grass is so much richer than ours so I thought I’d take advantage of it. What are you two doing out so late in the afternoon?"

David explained that they were trying to teach to cows to walk on a tightrope and the Martian laughed. "Are you having any success?" he asked.

"Not much," admitted David and the Martian cow herder laughed again.

"Let me show you how it’s done," said the cow herder and he took his blue cows over to where the tightrope swayed between its two ramps. The cows followed him obediently in a nice straight line and in single file. David raised a hopeful eyebrow to Nathan. Already the Martian cows were doing more than he’d ever been able to persuade Daisy and Buttercup to do. The cow herder put the tip of a tentacle in his mouth and whistled. He gestured at the first ramp. The Martian cows ambled up the ramp and walked nonchalantly across the rope. When they reached the far end of the rope, they climbed down the other ramp and started to crop the grass again as if nothing out of the ordinary had happened.

David looked at Nathan and Nathan looked at David and they were both of one mind. All their problems were solved. They had found the perfect cow. "Hey mister," said David, "can we borrow your cows for the Agricultural Show next week?"

The Martian cow herder looked dubious. "I’m not sure about that," he said. "I’ve entered them in a line dancing competition back home."

"Line dancing?" asked Nathan.

"Martian Line Dancers for Jesus," said the cow herder. "Surely you’ve heard of it. It’s very big among cow cockies."

"No," said David. "That’s a new one on me. But I presume it’s the line dancing discipline that makes your cows so good at walking the tightrope?"

"That’s right," said the Martian. "Line dancing judges are very strict. I’ve been working really hard to bring this herd to the peak of perfection. "

"We only need two cows," said Nathan. "How about we swap Daisy and Buttercup for two of yours?"

"OK," said the cow herder. "That might work. Frisians and Herefords are really exotic breeds on Mars. I’ll get a lot of brownie points in the competition when Daisy and Buttercup start dancing even if they turn out to be useless!"

"Which they probably will," muttered David to himself. "They are useless at everything."

The six blue Martian cows had eaten almost all the grass in the paddock and they were now just chewing the cud, their jaws working rhythmically from side to side. "I think they are full," said the Martian. "It’s probably time to take them home." Four of the blue cows ambled up the ramp into the spaceship. The cow herder whistled at Daisy and Buttercup and after a short hesitation they too walked into the spaceship. The ramp withdrew, the hatch closed and the spaceship flew off into the wild blue yonder. David and Nathan looked at the two blue cows and the two blue cows looked at David and Nathan.

"We’ve only got one problem to solve now," said David.

"What’s that?" asked Nathan.

"The cows are blue," said David. "People might get suspicious when they see blue cows walking across a tightrope. We might get accused of cheating."

"There are some cans of white and black paint in the barn," said Nathan. "We can easily turn the Martian cows into Frisians."