Imka put her head in her hands. ‘This is a nightmare. What is going on?’

‘I don’t know,’ said Nina, ‘but we’ll get out of this.’

‘How?’

‘Let you know as soon as we’ve figured it out,’ Eddie rumbled.

The men setting up the winch tossed a rope into the mausoleum, those below securing it around the sarcophagus. Harhund checked a reading on a device, then pulled off his mask. ‘It is safe,’ he announced. ‘Bring the prisoners down here. Tell them to leave their gear.’

A guard gestured with his gun for Eddie and Vorster to descend. They reluctantly discarded their equipment by the altar and went down the stairs. The Yorkshireman sniffed the air. ‘Someone have an egg sandwich for lunch?’

That produced chuckles from his captors. Harhund was not amused. ‘Shut up. No talking, or I will make the women suffer.’

‘Wouldn’t recommend it,’ Eddie told him with barely veiled threat.

Harhund merely sneered. ‘Help the others lift it. But do not damage it. I will not need to shoot you if any gas escapes.’

Vorster and Eddie exchanged concerned looks, then joined the mercenaries to lift the sarcophagus. The Englishman noticed a lead pipe protruding from the floor, its end blocked by some kind of epoxy or superglue. As the men tilted the coffin, he saw a similarly plugged pipe in the bottom of the crystalline cylinder. The realisation that it still contained a deadly gas made him handle the heavy object with much more care.

They manoeuvred it between the other sarcophagi towards the exit. Once it was clear of the obstacles, the powered ascender was switched on to help haul it up the steep stairs. Even with the machine’s assistance, it was still a strain, but the glinting coffin and its bearers finally reached the throne room, Eddie giving Nina a look to assure her that he was still watching for any opportunity to escape. On the smooth floor, the sarcophagus’s journey was much faster. It soon reached the entrance.

Harhund shut down the ascender and ordered two men to set up ropes in the curving corridor for the next leg of the ascent, then gave his prisoners a coldly thoughtful look. ‘You, go back down,’ he ordered Eddie.

‘If you don’t need me any more, I could just go home,’ Eddie replied.

The Norwegian did not respond to the jibe. ‘The rest of you, follow us. Braun, guard him,’ he told the man watching Nina, Cheng and Imka.

‘Where are you taking us?’ demanded Nina. ‘And why are you leaving Eddie here?’

‘To make you do as you are told,’ was the blunt answer. ‘Now move.’

Nina reluctantly set off, the others following. She glanced at the altar – and stopped in her tracks.

Cheng almost bumped into her. ‘What is it?’