Everybody did as Sergeant Rowan suggested, because the sergeant just had that way about him. Even though they were trapped in a region that was generally agreed to be the last place in which anyone wanted to end up, with no idea of how they had got there, and no idea of how they were going to get back, they were willing to follow Sergeant Rowan because he had Authority. He had gravitas, which means “seriousness” for those who don’t have a dictionary to hand.

And he had a big truncheon that he waved meaningfully at the dwarfs in order to encourage them to make the right decision. In these situations, Sergeant Rowan had found, waving a big stick always helps.

Meanwhile, back in that small room supposedly being used for the storage of cleaning products and brooms, Professor Hilbert was engaged in an animated conversation with Victor and Ed. He had just concluded a similar conversation with Professor Stefan, a consequence of the small loss of energy that had occurred shortly after the Collider had been turned on again. Professor Stefan, Hilbert felt, had become slightly hysterical at the possibility that all those demons might start popping up again, although this stemmed as much from his understandable fear of being eaten as from his concern that, if the gateway to Hell did open for a second time, someone would find a way to blame him for it. It had taken all of Professor Hilbert’s considerable diplomatic skills to convince Professor Stefan not to close down the Collider again, or not yet. Now, in the broom closet with Victor and Ed, he was using some of his other skills, namely the ones linked to bullying staff in a gentle manner in order to get his way.

Professor Hilbert was a believer in the “hidden worlds” theory, the idea that there might be universes other than our own somewhere beyond the realm of our senses. He also felt that particle physicists were spending far too much time worrying about the nature of atoms, and refracting light, and other relatively mundane matters related to this world that actually exists, and too little time speculating on the nature of worlds that might exist elsewhere.

Here’s the thing: We know that everything we can see around us is made up of some fairly elementary particles, and that various forces, like gravity, help to keep the whole process of existence moving along smoothly without people floating off into the ether or spontaneously collapsing into a muddle of atoms. But suppose that there were other particles, and other forces, operating alongside us, which we couldn’t perceive because they were beyond the limits of our powers? That would indicate that the cosmos was a great deal more complicated and interesting than it already appeared to be.