The sword was where he had left it. He took it carefully from its hooks, lifting it easily upwards. It was in an unprepossessing sheath made from tough leather, and an obviously ancient, well-worn leather belt went with it. Girding himself, he felt suddenly ridiculous. He had never used a sword before. What on earth was he meant to do with it now? But the thought of it gave him strength, even though he was not sure he would be able to harm Jack with it.

The stairs loomed. The corners seemed further away, the height greater, shadows spilling where there should be no shadows. The hairs on the back of Tom’s neck and arms began to bristle, and an unpleasant shiver passed over him.

Tom paused at the bottom, and a clock chimed, startling him. He had lost all sense of time. It was eight o’clock. He put his hand to the banisters. What might bring Jack away from his travels in the web of time? Carefully, Tom trod up the steps as softly as he was able.

The first-floor landing was dark. Tom was glad that Jack’s rooms were the furthest away from the stairs. He pressed his back against the wall and edged carefully upwards. The sword clanked uncomfortably.

Reaching the attic landing, he found it normal. The door to the seventh room was firmly closed. Tom steeled himself and, gripping the sword handle, went inside.

He blinked.

Ahead of him, instead of the small attic room he had been expecting, was a wide, spacious chamber, panelled with dark oak and richly furnished, tapestries hanging on the walls, gilt-framed pictures and well-upholstered chairs. A beautifully carved chess set stood on a table, although there seemed to be more pieces than were usual, and some of them Tom could not name. There was a smell of fresh polish and in a glass vase was a spray of gorgeous white and blue flowers that looked like nothing he had ever seen in the fields or woods.

Tom checked over his shoulder. The corridor was the same as it had been.

Feeling a little uncertain, he stepped back into the large wood-panelled space. The tapestries hanging on the walls glowed with rich reds and golds and greens. The designs were sometimes geometric, sometimes figurative.

As he stared at them, they took on a greater meaning, and for half a second he felt like he was on the edge of some immense truth. But almost as soon as he thought he had grasped it, it slipped away, leaving him gasping in disappointment.

The room was long and rectangular, and at the other end of it was another door, decorated with gold, an inscription above it in a language Tom did not recognise but which he immediately understood.

A shadow comes from light.