She must have paid for the experience, but whether she paid here in this world or in some other dimension that fluttered her through like some existential tourist seeking strange thrills, I have no way of knowing. I only see her floating in her perfect sphere, looking for all the world like a fairy blown through a soap hoop into the sunlight of a child's daydream.

But in her hands she has a very real device, a scroll of technology, by which she seems to be navigating. Her face is a picture of concentration - all unselfconscious lines, none of the taut muscles of a determined-to-be-impressed sight-seer. So perhaps she isn't a tourist after all but a scientist, someone with more than a passing interest in out world.

                                

But why is she floating above this smouldering heap of geology? And where on Earth is this smouldering heap? I want to say Mexico, but a lot of what I want to say in wrong. Perhaps it's Brazil. Certainly there are tropical trees all around, as far as any eye could see, like a carpet undulating away. No doubt they are filled with monkeys, big, loping butterflies and insects yet to be discovered, even by us.

So if scientist she is, how to explain her clothes? Well, scientists can dress colourfully, can't they? They don't have to wear white coats all the time, especially when they're out in a world. I like her shoes especially. With their curled-up toes, they look like a medieval jester's. Such superfluousness in one so precise would seem out of place - if she really were a scientist.

But all of this is just projection. Indeed, she might be a hundred percent a product of my imagination were it not for that map, which is far too sharply defined to be dreamed. I see it glowing, making a blue cave of her hands. Part of me thinks it's downloading data from the crater, as it were. What data does a volcano give off? I'm afraid I'm not an expert, and since it's only me here, I can't ask anyone. Perhaps you know, but by the time you read this, she'll have gone, I'm sure. Her bubble will have popped her back to wherever she came from. Even now I can see it quivering hesitantly, but that could just be atmospherics - there's a lot of it about.

Now she's heading right into the plume. Her face has left her screen, which has been rolled up, placed inside her belt along with other handy accessories. Her eyes, bigger and bluer than ours, are scanning that plume as if seeking a silver lining or a security strip woven into its substancelessness. Looking at those eyes, I could almost fall in. I'm the boy at the edge of the deep, unknowable well. But it's not good to dally on the brink. Either stay away or make the leap - like her.