‘What’s the matter?’ Galen sat carelessly against the slabs of the tomb, his coat tugged tight around him. ‘Scared of moths now?’

Raffi dumped the wood in a heap; dust rose from it. ‘One of the sense-lines just snapped!’

The keeper stared at him for a moment. Then he turned to the fire and began piling the wood on to the flames. ‘Did it now.’

‘Don’t do that! Someone might be coming!’

Galen shrugged. ‘Let them.’

‘It could be anyone!’ Raffi dropped to a crouch, almost sick with worry, the strings of purple and blue stones he wore round his neck swinging. He caught hold of them. ‘It could be the Watch! Put the fire out at least!’

Galen paused. When he looked up, his face was a mask of flamelight and haggard shadows, his deep eyes barely gleaming, his hook nose exaggerated like a hawk’s. ‘No,’ he said harshly. ‘If they want me let them come. I’ve had enough of skulking in the dark.’ He eased his left leg with both hands. ‘What direction?’

‘West.’

‘From the mountains.’ He mused. ‘Could just be a traveller.’

‘Maybe.’ Raffi was preoccupied. Another line had twanged in his skull, closer now.

Galen watched him. ‘So. Let’s put my pupil through his paces.’

‘What, now!’

‘No better time.’ He turned his lean face to the fire. ‘If it is an enemy, what might we put on the flames?’

Raffi, appalled, rubbed his hair. He was scared now; he hated Galen in this mood. ‘Bitterwort. Scumweed, if we had any. Goldenrod to make him sleepy. Shall I do that?’

‘Do nothing, unless I tell you. Say nothing.’ Sharply, Galen raised his head, his profile dark against the smallest moon. ‘Have you got the blue box?’

Raffi nodded; he clutched it in his pocket.

‘Use it only if the danger is extreme.’

‘I know, I know. But –’

A twig snapped. Somewhere near by a were-bird shrieked and flew off through the branches. Behind it, Raffi caught the snuffle of a horse.

He stood up, heart thumping. Behind him the cromlech was black and solid, the rock-face gnarled under his palms, hollowed by a thousand years of frost and rain. Lichen grew on it, a green powder over the faint carved spirals. It felt like a great beast, fossilized and hunched.

Galen pulled himself up too, without his stick. His long hair swung forward, the tangled strings of black jet-stones and green crystal catching the light, the heavy cowl of his coat high around his neck.

‘Ready?’ he breathed.

‘I think so.’

The keeper gave him a scornful glance. ‘Don’t worry. I won’t risk your life.’

‘It’s not mine I’m worried about.’ But Raffi muttered it sullenly under his breath, feeling for the powders and the blue box.

A horse came abruptly out of the wood.