In short, it was hard work, and it required all of their attention, speed and energy. Sometimes they had to think quickly and move fast, at others they had to wait.

At one point when they stopped inside a blockhouse, Jack peered down the full length of the maze.

It stretched away into infinity, mind-bogglingly complex.

Every now and then, he glimpsed the moving flashlights of Rastor’s and Sphinx’s teams up ahead, moving steadily onward.

Jack checked the time.

It was 5:00 p.m. local time, 28 December.

‘We’ve been going for over twelve hours now and it’s going to take us many more to get through this thing. The Omega Event is going to occur at 3:06 a.m. GMT on 29 December. That’s 5:06 a.m. local time.’

Zoe looked at her watch. ‘So we have another twelve hours, that’s all?’

‘That’s all,’ Jack said. ‘Twelve hours to get to the Death Throne. Sphinx wants to sit on it, while Rastor wins if he destroys it or if he stops anyone else sitting on it.’

He took a deep breath as he looked at the others.

‘Keep going, everyone. We can’t stop, no matter how tired we are. We can sleep after we’ve saved the universe.’

And so they progressed through the deadly rotating maze.

At times they made swift progress.

They even managed to get through a few rotations while standing on some of the diagonal bridges.

That was Zoe’s idea, as a way to speed up their travel.

They would clamber along an upward-sloping diagonal bridge, and then, as the maze around them turned, its mighty gears grinding, they would stop, balancing carefully in the middle of the diagonal bridge.

Then the maze would rotate and the bridge would go from upwardly sloping to downwardly sloping. When the turning stopped, they would just keep running down it, onto the new ‘floor’.

But more often, their progress was slow and they would only manage to make a short hop from one blockhouse to the next.

At other times, they made an error and had to hurry back to the previous blockhouse, so they didn’t get stranded out in the open-topped trenches.

And then there were the occasions when they found themselves on a wall, where progress was extra difficult and slow, crawling and walking on the shelf-like walls of the trenches.

And, of course, there were those times when the rotation of the maze brought their blockhouse to the ceiling: at those times, they had no choice but to stay put inside the fully upside-down blockhouse till the next turn of the maze.

About five more hours in, they were working their way along a side wall when suddenly the maze not only turned sooner than anticipated, it turned upward not downward, and they were still twenty metres short of the next blockhouse.