It was hard in the half-light to pinpoint exactly where the music was coming from, too many hard surfaces for the sound to reflect off, and as they wove among the shelves it seemed to sometimes get quieter and sometimes louder. Blue listened hard until he was fairly sure he had pinpointed the direction they should be heading. Of course that didn’t mean the things, whatever they were – monsters? – would be there. But it was all he could think of at the moment. He kept expecting that croaky voice to come floating out of the darkness again, shouting ‘Warmer’ and ‘Colder’ like in a child’s game. At last they cleared the end of a row and he saw an open metal staircase leading to a raised platform. There was a lit candle on every step. At the top was what looked like some kind of an office, some four or five metres above the warehouse floor.

‘Do we go up?’ Einstein asked.

‘It’s what they want,’ said Blue.

‘Is it what we want?’

‘Do we have a choice?’

‘Guess not,’ said Einstein.

‘Achilleus, you take point,’ said Blue, almost whispering. ‘We’ll follow on behind.’

‘Sure.’ Achilleus shoved Paddy out of the way. ‘Paddy, dress back, yeah?’

‘I need to stick close to you, I’m your helper. I can fight.’

‘No to all three, soldier. Not right now. I want a proper fighter at my back, not a caddie. We don’t know what’s up there and I don’t want to be worrying about you.’

‘But Achilleus.’

‘Shut it and do what you’re told, you little rat.’

Scowling and muttering, Paddy dropped back and Jackson took his place. Achilleus looked her up and down and nodded his acceptance. The stairs would only take two people safely side by side, and even then they’d be getting in each other’s way if they had to fight. So Achilleus made sure he was in front with clear space around him. He gripped his spear with both hands widely spaced. It wasn’t the best weapon to use in cramped conditions, but it was the best he had.

He started to climb. The stairway had one return halfway up, where it switched back on itself. Achilleus reached that point safely and waited for the others to join him before proceeding. He wasn’t taking any chances.

They clattered on up to the top. The sound of the jazz was much louder here, though it was slightly tinny and distorted. It was a long time since Blue had heard any recorded music. A couple of his mates had played guitars back in Morrisons, but this was different. He’d almost forgotten what proper music sounded like. This was all brass and drums and piano, a driving beat, but something from ancient history. Old and weird to Blue’s ears.