Conversation was limited as the group headed deeper into the forest, the Aelfirian guide speaking least of all. Leading the way, she kept the pace of their progress slow for Denton, who grumbled now and then about his old legs and aching joints.

Marney opened herself to her surroundings, dropped her emotive defences, and allowed the sights and sensations to wash over her. She chuckled to herself as she waved away curious insects, and savoured the texture of the bark beneath her hand, and the smell of dirt and moss that stained her skin. Sturdy roots weaved in and out of the forest floor like dead tentacles. Above, through the thick green canopy that whispered in the damp breeze, sunlight winked between gaps in grey clouds. The Trees of the Many Queen was a good House, a peaceful forest, and it seemed far from the troubles that might be waiting ahead for Marney and her mentor.

The terracotta jar that had contained the essence of Fabian Moor had been found in a mysterious House called the Icicle Forest. Van Bam and Angel were on a mission to Mirage, to investigate an Aelf called Ursa, the one responsible for transporting the jar to the Labyrinth and reanimating Moor's essence. Marney and Denton's mission was to learn more about the Icicle Forest.

Even Lady Amilee had no information about that place. It was thought to be a Genii stronghold, a secret House hiding in the Nothing of Far and Deep, where Spiral plotted and planned against the Timewatcher. If the location of the Icicle Forest was to be revealed, if any information on this enigmatic House existed, then Lady Amilee believed it would be found at the Library of Glass and Mirrors.

The task ahead of Marney suddenly seemed so daunting that the beauty of her location became as dull as the sky.

After an hour of walking, the humidity broke and the temperature dropped. A fine drizzle misted the air and collected on leaves, dripping down on the travellers. After another hour, the light began to dim and the drizzle turned to hard rain. When Denton asked for a rest, the Aelf led the empaths to a log shelter with one exposed side, standing beside a forest stream. A ring of stones had been laid with dry wood on the shelter floor, and the Aelf set it ablaze with tinder and flint. She then took a black iron kettle from a hook on the wall, filled it with water from the stream, and hung it over the flames to boil.

The Aelf left the empaths alone, saying that she needed to scout the area. Marney suspected that in truth, she just didn't want to overhear anything they might discuss of their mission. Alone and soaked to the skin, the empaths sipped green tea and feasted on hard oatcakes.

'I'm really not cut out for this kind of lark, anymore,' Denton grumbled as he rubbed his knees. 'Not sure that I ever really was, to be honest.'

Marney said nothing and stared into the flames.

'I wonder how the others are getting on,' Denton said after a while. 'I've been thinking about them. You?'

Marney looked at him. 'Hmm?'

'The others,' Denton said. 'I wonder if Samuel and the twins have located Fabian Moor yet.' He lowered his eyes at her. 'I wonder how things are going in Mirage?'

Marney smiled sheepishly. 'Yes, all right, I was thinking about Van Bam.'

Denton squinted at her. 'What's that you've got?'

It was a small, open tin that Marney held in her hands. She had taken it from her backpack, and it was filled with light brown crystals that carried an aroma not out of place in the forest.

'Bath salts,' she told her mentor in a quiet voice.

Denton chuckled. 'You brought bath salts with you? On a trip like this?'

'Yes – no – I mean, I wanted to bring them because ...' She felt too embarrassed to finish the sentence.

'Ah,' said Denton. 'They were a gift from Van Bam?'

'I know it's stupid, Denton, but I'm comforted by the smell. It reminds me of him.'

'Nonsense – I think it's very sweet,' Denton replied. 'What do they smell of?'

'Sandalwood.'

'Your favourite scent, if I'm not mistaken.'

Marney lifted the open tin to her face and sniffed. 'I can't quite explain it, but the smell of sandalwood reminds me of good things – nothing specific, it's just ... like smelling happy memories. Does that make sense?'

'Perfectly,' Denton said with a smile. 'Smells very often become associated with memories. And emotions. Perhaps most especially for empaths.'

Marney nodded. 'I like to think that one day someone might smell sandalwood and remember me.'

'And I'm sure they will.'

Marney closed the tin and returned it to her backpack. 'It seems strange, don't you think? I mean – that we have to keep secrets from the others, that we can't tell them about this mission? We're fighting on the same side in this war.'

Denton paused before picking up his wooden cup and draining it of tea. He poured himself another, and then set it aside to cool.

'I have something for you,' he said. 'Nothing as charming as Van Bam's gift, I'm afraid.' He undid the straps of his rucksack, dipped his hand inside, and produced a fat envelope. 'This must be kept safe,' he said, holding it out to Marney. His eyes were intense, ensuring that he had her full attention.

Marney couldn't explain why, but she was reluctant to take the envelope, and kept her hands in her lap. She could see that the wax seal had been stamped without a symbol.

'There are often good reasons for secrets.' Denton's expression was sympathetic but firm. 'We are heading into the war, and it would be ignorant for us to believe that our lives are not under threat, yes?'

Marney nodded.

'There are certain aspects to what we are doing that I cannot tell you about,' Denton continued. 'However, this envelope contains every detail of our mission. But there is only one occasion on which you must open it. Do you understand what I am saying?'

Marney looked away, unable to hold her mentor's gaze, not wanting to hear where she very much understood this conversation was leading.

'If I should be killed—'

Marney recoiled from his words.

'Listen to me, Marney,' Denton said sternly. 'If I should be killed, it will fall to you to complete this mission. In this envelope you will find coded instructions on how to find the Library of Glass and Mirrors, and what to do once you get there.' He jabbed the envelope toward her more forcefully. 'You are an agent of the Relic Guild, and I need to know you will do what is necessary, no matter what.'

'Of course I will,' Marney said, more angrily than she meant to.

'Then take the bloody envelope, Marney.' Denton was almost pleading. 'If it comes to it, you decipher the instructions, memorise them, destroy the evidence, and report everything that you discover only to Lady Amilee.'

Marney sealed up her emotions. To any other person she would have disappeared from perception. It was an act of self-preservation, a desperate bid to stop herself admitting that what she feared more than this mission was to be alone. She was terrified of the day when Denton was no longer around and she would have to face the world without his tutelage and guidance.

Without meeting his eyes, she took the envelope.

Denton sent her a wave of hopeful and affectionate emotions. 'This is only a backup plan, Marney. I sincerely pray to the Timewatcher that you'll never have to open that envelope.'

She looked at him and saw his eyes had become distant.

'Trust me,' he whispered. 'Not all Houses are Aelfirian, and there is a reason those Houses are not connected to the Labyrinth. There are places out there that you really don't want to know about.'

She frowned and made to stuff the envelope into her rucksack.

'No,' Denton said. 'Put it on your person – safe and close.'

Marney slipped the envelope into a leg-pocket on her travelling fatigues, and buttoned it up tight. She patted the pocket and gave Denton a nod to affirm that she understood her instructions.

'Always be mindful that you have it, Marney,' Denton said seriously. 'It's said that anything that can be known is known by the librarians at the Library of Glass and Mirrors. You don't need me to tell you how much the information in that envelope would be worth to the wrong type of people.'

'You can trust me,' Marney said, and sent her mentor a wave of emotion, letting him feel her sincerity.

'That's my girl.' Denton smiled. 'Here, have more tea.'