‘That path leads towards the Earth. Take it and she will follow you,’ Thanatos said solemnly. ‘I swear it.’

‘How will I know the way?’ he asked.

‘I believe you have Ariadne’s golden string at your disposal?’ said Thanatos, nodding at the bag.

Elliot scrabbled in the bag and pulled out the ball of twine given to him by Theseus. He held a loose end and threw it to the ground, where it immediately unfurled, lighting a thin golden path ahead.

‘Time to Earth: one hour,’ chimed Ariadne’s voice. ‘Traffic conditions are normal. And all men are faithless pigs.’

Elliot nodded and set off resolutely towards the tunnel. The sooner he got out of here, the sooner he got his mum back.

‘Oh! Just one more tiny detail!’ Thanatos called after him.

Elliot stopped dead. He knew it.

‘Nothing to worry about – just make sure that, no matter what, you don’t turn around. To look at her, I mean.’

‘What do you mean?’ Elliot said. ‘Why not?’

‘I don’t make the rules,’ Thanatos sighed, reclining on a nearby rock. ‘Indeed, there’s only ever been one case of a soul being escorted to Earth – by young Orpheus. And that ended . . . Well, don’t worry your head about it. You just walk to Earth without turning around.’

‘And what if I do?’ said Elliot stubbornly. Even now, he didn’t like being told what to do. Especially now, perhaps.

‘Well, it’s up to you, of course,’ said Thanatos. ‘You can if you want. Orpheus looked at Eurydice . . .’

‘And it was the last time he ever did!’ Nyx screeched, gleefully. ‘Because if you look at a soul – even the briefest glance – it will return to the Afterlife. For ever.’

Elliot took a deep breath. So all he had to do was walk his mum back to the Earth without looking back. Couldn’t be that hard, surely?

‘Last thing,’ Thanatos said, handing Elliot a scroll of parchment. ‘Kindly give this to Zeus when you see him. It’s an . . . invitation I’m sure he won’t want to miss.’

‘Zeus and I aren’t friends any more,’ said Elliot, feeling a pang of regret poke his heart.

‘Oh, you’ll make it up. You do-gooding types always do. Just make sure he gets it. He’ll want to see what I have in store . . . Well, you’d best be on your way,’ Thanatos said, pulling the Chaos Stone out of his robes again. ‘Goodbye, Elliot Hooper. Truly, it has been a pleasure doing business with you.’

‘And watch your back,’ Nyx called after him. ‘After all, you never know who you can trust.’

Elliot swallowed down the hatred coating his throat. Nyx would have to wait. He walked towards the tunnel, the Daemons’ laughter ringing in his ears. But he didn’t care. The only thing that mattered now was getting his mum safely back to Earth.