"What on earth is a Time-traveller?" asked Mollie, rather surprised to find that she did not feel in the least alarmed at this sudden apparition.
"A person who travels in Time," the child replied. "I am one, and you are one, but everybody isn't one. I can't explain, so you'd better not waste time asking questions if you want to travel. I can't wait here long."
"But—" said Mollie, looking bewildered, as well she might. "Travel where? Of course I'd love to come, but how can I with a crocked-up ankle; and what would Grannie say?"
"Those things don't matter to Time-travellers," said the other child. "We travel about in Time. You haven't got to think about what is happening here and now—that will be all right. But you have to make a vow before you begin Time-travelling. Do you know what a vow is?"
"Of course I do," Mollie replied; "I'm a Girl Guide."
"I don't know what a Girl Guide is," said the other girl, wrinkling up her pretty forehead, "but a Time-traveller has to vow on her faith and honour never to say one single word about her adventures to any grown-up, either here or there. You must not ask them questions that will make them wonder things, however much you want to, because they don't understand, and would be almost sure to interfere. Will you vow?"
"Yes, I will, but you must give me one moment to think. Where shall I travel to and how long shall I stay?"
"You come along with me to my Time; I don't know how long you will stay. A year of our Time might be a minute of yours, or a minute of ours might be a year of yours, but you will be all right. Have you ever seen a dissolving view?"
"That's a magic lantern, isn't it? Yes, Dick once had one. I think they are rather dull."
"Oh no, not if they are properly done. Hugh—" she stopped and then began again. "You will step into a dissolving view of our Time. It just begins and ends anyhow, and you go out of it again."