“ ‘I’m saying things exist in this world that look human but aren’t human, and there’s no real telling how many species of these there are. There are beings walking the Earth fully disguised as humans, deliberately fooling us. So when it comes to a spirit, you never know what you’re dealing with. It could be something good and loving, like Goblin.’ She glanced at him. In fact, she smiled at him. ‘Or it could be the ghost of something dreadful that secretly despises humankind and wants to hurt it. But the main thing is to understand that all spirits have a kind of organization.’

“ ‘How do you mean?’

“ ‘I mean that even though they’re invisible to most people, they have a perceivable form and a nucleus of sorts in which the brain and the heart reside together.’

“ ‘But how do you know?’ I said. ‘And how is that possible?’

“ ‘Well, first off,’ she said, ‘it’s what Stirling believes and he’s been studying ghosts his entire lifetime. That’s why he’s spending so much time of late with me. I see ghosts constantly. And it’s also what Rowan believes, you know, my cousin Dr. Rowan Mayfair.’

“ ‘But where is this nucleus? And how is it that a ghost can appear and disappear?’

“ ‘Science hasn’t caught up with it yet,’ she said, ‘that’s what Rowan is always telling me. But we have definite ideas about it. The nucleus and the particles that make up a ghost are simply too small to be seen by us and the force field that organizes them can pass effortlessly through the molecules that we can see. Think of tiny insects and how simple it is for them to pass through hardware cloth. Think of water passing through cotton or silk. That’s the way ghosts pass through walls. It’s all there to be known someday but right now we don’t know it.’

“ ‘Yes, I see what you mean, as to how the ghost comes and goes through matter, but how does it appear to us?’

“ ‘It draws particles of matter to itself magnetically and organizes them into the illusion. The illusion can be so strong that it looks and feels solid. But it’s always an illusion, and when the ghost wants to disappear, or has to disappear, the particles are diffused.’

“I was too entranced to argue with her. She took it very seriously, what she had to say, and all I had really were questions. But I knew that Goblin was listening too, and I would have been more frightened on that account if I hadn’t known she knew it also.

“ ‘Now, some ghosts,’ she said, ‘those that are really strong, can make themselves so solid that they’re visible not just to one or two receptive persons but to everybody. They’re there,’ she said. ‘And God only knows how many of those ghosts are walking around among us.’