The bell rang for the end of recess, but Matt wasn't going back to class. He was going to the principal's office.

Had the man in black seen him take something from the dead man and put it in his pocket? Maybe. If so, he would have told the police. They'd want to check Matt's bag. They'd find the pouch. And they'd take it from him, because it was EVIDENCE. He would never see it again.

This didn't occur to him until he had reached the library. He stopped there to think about it for a moment. The principal's office was through a pair of doors and down a short corridor past the admin ladies. He looked around the library. There was nobody here. It seemed especially gloomy today, as if a storm had sprung up outside – but he had been outside a moment ago, and it had been clear, so it wasn't that. Perhaps Mrs Ritchie the librarian had forgotten to turn the lights on. He decided he would stow the bag away somewhere in here and come back for it later. Taking a last look around to make sure nobody was watching, he slipped into one of the aisles.

And stopped in his tracks. Because something floated there, in the centre of the aisle, about a foot above the carpet.

It was a great metal ring. It was taller than he was, and perfectly round. How it was suspended above the floor he had no idea, for nothing appeared to be holding it up, though it must have been heavy. It was as thick as the thickest part of Matt's arm. His first thought was that it was made of iron, for it was dark and dull with age, but the colour was slatier. It reminded him of fishing sinkers. It was unmarked but for a pair of engraved initials at its apex. He had to step forward and peer up into the gloom to make them out.

J.D.

Most peculiar of all, he couldn't see the aisle through the ring. Only black nothingness like the space between stars. Faint sounds emanated from the darkness, but he could not make out what they were.

He thought about going and finding someone so he could show them what he had found. But would the ring still be here when he returned? He didn't know.

He reached out towards it, but drew his hand back before his fingers made contact. What had made him draw back was the smell. It was something that didn't belong in a library.

Last year his dad had taken him down the coast, where they had stayed with an old man called Roy, who lived near the sea. Exploring Roy's property, Matt had discovered three fox skins nailed to the back of Roy's shed to dry. He could smell them now. Fox skins. And the sea – yes, he could definitely smell that. A gull barked somewhere. But there were gulls at his school, plenty of them, and when the wind was blowing from the south you could smell the bay. There had been no wind at recess, but perhaps it had sprung up just now.

He edged around the ring, taking care not to touch it. On the other side stood the aisle, just like normal. Except for the initials, the ring was the same on the back. And the same darkness filled it.

His heart hammering, Matt reached out towards the darkness. His hand passed through it and vanished completely. He pulled it out again. His hand was still there. Curious.

An idea occurred to him. Later he would wonder where it had come from. Because he didn't have to hide his bag inside the ring. He could have hidden it anywhere, really. Nevertheless, he took his bag off his shoulders and pushed it into the darkness. It vanished just as his hand had done. Holding one of the straps he let the bag descend. It stopped roughly where the library floor was. He let it go.

Before he could change his mind he pulled his hand back out, squeezed back past the ring, took one last look at it, then left the aisle, heading for the principal's office.

Stuff it in your ring.