By five o’clock, Harry was sure it was gone. It wasn’t on his dresser. It wasn’t under his dresser. It wasn’t anywhere to be found on, under or in his bed, floor, shelves or cupboards. It was gone. Vanished. MIA.

This was not a good thing.

“Harry? What’s all that banging about?”

Harry sucked his fist. Walls were tougher than they looked. “Nothing, mum. Just lost something.”

“Well, can you lose things quietly for a change?”

With eight thumps and a squeak, his mother returned downstairs. Harry sat down on his bed.

“Bugger.”

The word was spoken softly and didn’t seem to adequately describe the situation.

“Bloody bollocks!” he tried, a little louder.

Still not quite enough.

“Sh-...”

“And mind your language!”

Harry rested his head in his hands. Why now? Of all the billions of possible points in his life, why did it have to be the Friday before exam week that his lucky penny went missing?

“Bugger,” he repeated, softly this time. He stared sorrowfully at the floor.

That was when he noticed the signs of an intruder. A glistening trail, like a streak of varnish, leading from the base of his dresser and disappearing underneath his bed.

Harry frowned. As far as he was aware, an eleven-year-old’s bedroom wasn’t a common place to find a snail. He looked beneath the dresser. No snail there. He looked beneath the bed.

“Hello? Mr Snail?”

He paused.

“Or Mr Slug.”

There was no answer and no creepy crawly. There was, however, a hole in the plaster, right in the back corner. The glistening trail disappeared into it.

Eight thumps and a squeak later, he was downstairs.

“Stop crashing about!”

“I wasn’t!” Harry returned, heading out the back door.

From outside, it was easy to pick out his window by the Fulham FC transfer. A little way below the ledge was a tiny hole in the brickwork. And a shiny snail-trail.

“Gotcha.”

The trail led all the way down to the ground and across the patio. Crouching low, like a jungle explorer, Harry followed it. The trail ran, straight as an arrow, down the bowling-green lawn, before disappearing behind a thick bush.

Harry scooped some of the green growth out of his way to clear a viewing port. Behind the bush were enough snails to stock all the restaurants in Paris. They were slithering and sliming over everything. The ground, the fence, each other…and a strange object, about the size and shape of a large cake tin.

It appeared to be comprised mostly of old biros, but there were also paper clips, pencil stubs, bottle tops and bits of mobile phone case, all held together with pieces of chewing gum. On the very top of the structure, a muddy brown snail was waving its eyestalks. Harry got the strangest impression it was trying to get everyone’s attention.

“Ahem,” came a tiny voice. “I say, AHEM!”

The snails stopped milling around and directed their eyestalks towards the speaker.

“I am delighted to announce that, at long last, we are going home!” the snail said. “The Great Work is finished!”

Snails aren’t very good at cheering, but they certainly made an attempt at it. The speaker waved his eyestalks for silence.

“Thanks to a gallant last foray by our dear Archibald, we have the final piece we need. In his dangerous quest, he risked life and foot to...”

“There cheers for Archibald!” someone interrupted. “Hip hip...”

“GASTROPOD!”

“Hip hip...”

“GASTROPOD!”

“Hip hip...”

“That’s my lucky penny!”

The snails froze. For a whole six seconds, silence reigned while dozens of tiny grey eyestalks slowly rotated in Harry’s direction. After an apparent eternity, it was broken.

“Emergency take-off!”

“Abandon bush!”

“Chocks away and ready the flight coordinates!”

“Full snail speed away!”

“No, wait!”

Before Harry’s eyes, the tiny creatures were piling inside their construction, slamming down bottle-top hatches and pulling in biro supports. In the centre of the structure, Harry’s lucky penny was starting to spin, turning with it an array of paper-clip and tin-foil blades. Slowly, the entire mass lifted off the ground.

“Wait!” called out Harry. “I need that!”

But it was too late. The snail’s craft was gaining height fast. Soon it was floating above the bush. Then above the trees. Then...

“It’s gone,” Harry murmured.

“Harry? Where are you? Your dinner’s ready.”

“I’m in the garden, mum!”

“What are you doing out there?”

Harry looked up at the sky.

“Nothing, mum.”

Parents are all very well, but they never believe anything.