‘Ready?’ he asked, rummaging about in a rusty toolbox and producing a hammer and chisel from it.

‘Only if you’re sure you know what you’re doing,’ said the cat, jumping up next to him.

‘What’s that supposed to mean? I thought you wanted to open it?’

‘I did! I do! I definitely did, for sure!’

‘What’s that supposed to mean?’

‘I don’t know. What if it’s just not meant to be opened? Maybe there’s a reason that it fell into the lake and all those men came looking for it.’

Arthur frowned at him. Placing the sharp end of the chisel into the faint line, he picked up the hammer. ‘OK, here goes nothing,’ he said and struck it gently but firmly. When nothing happened, he struck it again a little bit harder.

‘I don’t get it. I’ve hit it twice and there’s not even a mark on it.’

‘See. That’s what I was saying. Maybe it’s not meant to be opened.’

‘No… not a chance! It just needs a bit more effort, that’s all.’

And raising the hammer high into the air, he brought it down with such an almighty whack that he lost his grip completely, allowing it to fly out of his hand, narrowly missing his head and ricocheting off the roof. The chisel, launching in an entirely different direction, embedded itself into the far wall with a loud cracking sound.

‘You okay?’ Arthur whispered, having thrown himself on to the floor.

‘I think my whiskers have gone grey,’ meowed the cat, poking his head around the corner of the wood pile in the corner.

‘Really?’

‘Could be. Shocks like that can definitely age a cat!’

Taking a deep breath, Arthur raised his head up to see what had happened to the box. But it was just sitting there in the middle of the work surface, exactly where he’d put it.

‘But how? That’s not possible. I hit it really hard—you saw me, right?!’

At that moment, the latch on the door rattled, followed by a loud banging.

‘Arthur! You open this door immediately, do you hear me?!’

‘O-o, Cat!’ he said. ‘Now we’re in for it.’

‘No, not me, my friend, I’m just an innocent cat. And don’t forget to hide the box!’

Quick as a flash, Arthur stuffed it into the little pack which he always took fishing with him and put the hammer back. Attempting to retrieve the chisel from the wall, he found that it was in too deep and was forced to leave it.

‘Arthur! Open this door right now!’

With a last look around, he straightened his T-shirt and unbarred the door.

His mother was even more cross with him than he’d expected. Not only because going into the tool shed was expressly forbidden; but also, because, as luck would have it, she also spotted the chisel. The fact that he couldn’t give her a reasonable explanation as to how it’d gotten there only made matters worse.

‘So, you’re telling me that you have no idea how that chisel came to be stuck so far into the side of the tool shed wall that it can’t even be pulled out?’

‘Yes, Mama… I must have fallen over, and it flew out of my hand, I guess.’

‘You <<guess>>?’

‘Yes, Mama.’

‘And what were you doing with it in the first place?’

‘Trying to fix my backpack.’

‘Your backpack? With a chisel?’

‘Yes, well, I thought…’

‘Just you wait until Sasha hears about this. And what do you think your grandfather is going to say when he learns what you’ve done to his chisel, not to mention his tool shed. Again!’

‘I don’t know,’ said Arthur hanging his head, catching sight of the cat, who he was sure was grinning at him.

‘I don’t know, either! Now, get out of my sight while I decide what to do with you.’

And without needing to be told twice, Arthur grabbed his things and hurried back to the house.

‘So maybe you were right, Cat. Maybe it really can’t be opened,’ whispered Arthur, having crept up to the attic to avoid being seen.

‘A box that can’t be opened. It doesn’t sound very likely, or very useful, does it?’

‘What? You’ve gone and changed your tune.’

‘I never said it couldn’t be opened. I said that maybe we shouldn’t be trying to open it. Also, the more I think about the inscription on it, the more I think it sounds like a riddle.’

‘A riddle?’

‘Yep. And as you know, there’s nothing us cats love more than a good riddle. Especially when it’s raining and a small group of us have gotten together to pass the time.’

Arthur glanced at him in amazement.

‘What? Don’t tell me that you didn’t know that.’

‘Um, well I…’

‘See—just goes to show how much you don’t know about cats.’

‘Actually, I always thought that cats didn’t like each other much,’ said Arthur, recalling all the times he’d watched his cat seeing off the neighbours’ cat.