"But we've done it," said Mollie.

n.o.body answered. There did not appear to be an answer to that statement.

"Have you ever heard," Mollie said at last, speaking slowly and looking at the boys with solemn eyes, "of a thing called Einstein's Theory of Relat.i.ttey--I mean Rela_tiv_ity--Rel-a-_tiv_-ity?"

"Old Bibs jawed us about it one day," d.i.c.k answered, "but he said no one could understand it except the chap himself and not always him.

So he didn't expect us to, which was a good job for everybody."

"That's what Aunt Mary said; I heard her talking. That's why I read about it, because I'm fairly good at maths. She has it all pasted in a book. I had to skip most of it, but here and there I found bits. I took some notes," Mollie drew a penny notebook from her pocket. "One man says that, if the world travelled as fast as light, there would be no Time. All the clocks would stop, and we'd be There as soon as we were Here. Well now, that's just what we did. We were Here--and we were There. So our time stopped and Now was Then. See?"

"He says _If_. You couldn't live without Time. You _must_ have Time to do things in or where would you be? You'd have to swallow all the meals of your life at one mouthful and you'd bust. What comes next?"

"Another man says," Mollie read impressively, "that any schoolboy-- _any_ schoolboy," she repeated, fixing a stern eye upon her brother, "can see that, if the velocity of light has a given value with reference to the fixed stars, it cannot have the same value with reference to its source when this is moved relatively to the stars."

"Gee-whiz!" said d.i.c.k. "Next, please."

"A man says that perhaps things measured north and south are different from things measured east and west. _We_ travelled north and south. Perhaps we stretched back in Time all of a sudden, like elastic."

"Couldn't be done. Elastic stretches both ways. If _you_ tried to move north and south both at the same time you'd go off like a Christmas cracker. Next."

"A man says that our ideas of s.p.a.ce and time may be all wrong."

"Aunt Polly will agree with him if we stand here much longer," said d.i.c.k. "Next. Hurry up."

"You don't stop to _think_," Mollie said impatiently. "Try and _think_. Your head might just as well be a football. What _I_ think is that if two un-understandable things are discovered about the same time they must belong to each other. Don't you see _that_?"

"They might," d.i.c.k said cautiously, "and then again they mightn't. I don't think myself that there's any use trying to understand things like Time-travelling and Relativity. People like us never will."

"I don't know that," said Jerry, who had been listening to the discussion in silence.

"There's lots of things just as hard to understand, only you take them for granted. Being alive, for instance. Look at Mollie fidgeting about, and Long John chewing and twitching, and the trees waving their branches, and you shaking your head as if it were a dinner-bell, which is about what it is--it's all life. Just as hard to understand as Relativity, and a jolly sight harder if you ask me.

I can't say I understand Time-travelling, but--" Jerry broke off.

Mollie frowned thoughtfully. "We don't understand it _yet_," she said, "but in _another_ forty years--"

They were all silent. Another forty years!

"We'll be fifty-three," d.i.c.k said at last. "A jolly funny looking lot we'll be. All sitting round staring at each other through specs, with white hair and no teeth worth mentioning. I'll have an ear- trumpet, and Mollie will wear a cap like Grannie's, and Jerry will be a blithering old idiot saying, 'Hey!' like General Dyson-Polks."

They had to laugh at this picture of themselves, and then Mollie began at the beginning and told the story of Prue's first visit. The boys were deeply interested. Their own experiences had merely been a repet.i.tion of the first--Hugh had appeared and, like the gentleman who dealt in Relativity, they were Here and they were There. "It has taught us something about Australia anyhow," said d.i.c.k; "that is, of course, if we saw the real thing. The next thing is to find out whether we did or if the whole show was just bunk.u.m."

"What I should like to know," said Jerry reflectively, "is who the Campbells were, and how they got mixed up with your lot. They must have at some time, or your people wouldn't have those photographs."

Mollie smiled. She knew how they and the Campbells had got "mixed up", but she had never told the boys of her discovery; it was a little secret between her and a certain photograph that smiled down at her from the morning-room mantelpiece. She liked to think how the original would have laughed along with her.

"What I should like to know," said d.i.c.k, "is what that chap O'Rourke was doing in that field. What was his mysterious experiment, and how did Hugh's stone cut into it? That's what I want to know, and I don't suppose I ever will, now. I don't think we'll go back, not at present anyway. The show's over for this time. In fact I don't want to go; I'm too jolly well pleased to be where I am. Gee-up, you lazy brute,"--this to Long John, who apparently thought he had done enough work for one day and was nosing about the soft gra.s.s with contemptuous disregard for his pa.s.sengers. He moved on unwillingly, and d.i.c.k took him briskly downhill.

In the village there were old friends to be greeted, and many inquiries for Mollie's ankle to be answered. Fresh crusty loaves were brought out by the baker, loosely wrapped in soft paper, and packed away under the seats. A large box, containing a peculiarly delicious make of sponge cake, was set on Mollie's lap, and a blue paper bag of sifted sugar was entrusted to Jerry's special care by a misguided grocer. d.i.c.k had a golf-club needing attention, which entailed a long and intimate conversation with the local carpenter, who was also a well-known local golfer, and the best hand at repairing clubs, d.i.c.k was convinced, in the whole of Great Britain.

It was getting on towards tea-time when Long John's head was at last turned homewards, and his feet covered the ground with cheerful and approving swiftness. A drizzle of rain fell, "Just enough to save us the trouble of washing for tea," d.i.c.k commented. "Do you think our white aunt can be induced to come and play golf after tea, Moll, or is she afraid of rain?"

"Good gracious, no," Mollie replied. "Aunt Mary goes out in all the weathers ever invented. She will love a round of golf; she hasn't played since I sprained my ankle. I wish I could come too. I wonder if I could hop round with my stick and look on. I do love to watch Aunt Mary drive; I learnt a lot from her last week before I sprained my ankle in that idiotic way."

The boys negatived this proposal. "You'd get a ball in the eye to finish you up with," d.i.c.k said. "We'll plan some picnics till you are better, and explore the country a bit and knock some fat off this animal--hullo!--what's that?"

A sudden twist in the narrow road had brought into view a motor bicycle, leaning dejectedly against the hedge, whilst its owner squatted beside it and tinkered at its mechanism--tinkered in vain apparently, for, as the boys drew up beside him to offer a.s.sistance, he rose to his feet and shook his head hopelessly.

"Can we help you?" d.i.c.k asked, eyeing the bicycle with interest.

"I'm afraid we've got no tools here, but there is a smithy about a mile farther on and the chap there has a motor bike, so I expect he could lend you a hand."

"Thank you very much," replied the stranger, looking relieved. "I'll shove her along there and leave her. I am much afraid she's gone altogether phut for the time being, and will have to be trundled back to town by rail. Can you tell me if I am anywhere near a place called Chauncery?"

"Rather," d.i.c.k answered, with a grin. "That's our place. It's about half a mile up the next turning to the left."

"Indeed!" said the stranger, looking somewhat surprised and slightly dismayed; "I understood that it was occupied by Mrs. and Miss Gordon, not by anyone with chil--young people," he corrected himself hastily.

"So it is. But at present they've got us, owing to circs. We are Mrs. Gordon's grandchildren."

"Oh--I see! I hope that Mrs. and Miss Gordon are in good health?"

"Pretty bobbish, thank you," d.i.c.k was answering when Mollie interrupted:

"Can we give you a lift? We are on our way home, and I am sure it is going to rain hard presently."

"That is a very kind offer," the motorist replied gratefully, "and I wish I could accept it, as I am a trifle lame; but I can't very well leave my machine lying derelict by the roadside, and I fear that your hospitality cannot be extended to the old bus, I thought perhaps--if you would be so very kind--you might drop a message at the smithy you mentioned, and I will wait here until they send someone along."

But the word "lame" had roused all Mollie's sympathy. "How lame are you?" she asked. "Is it a wound? I am lame too--only a sprained ankle, but I should hate to walk from here to Chauncery."

"Of course you couldn't," the motorist said kindly. "I am not so bad as that. My wound healed long ago, but it has left rather a crocky foot behind. I could manage well enough, however, if someone from the smithy would come and push the bike."

"Tell you what," d.i.c.k suggested; "if you hop in and look after Mollie, Jerry and I will push the bike to the smithy; we'll be after you in two jiffs."

The stranger looked at d.i.c.k with a smile and a slight lift of his eyebrows. "You are very trusting, young man. Supposing I run away with the pony and the cart and the sister? What will you do then?"

"Stick to the bike," d.i.c.k answered promptly, "I have been wanting one most frightfully badly, and Father says I might as well ask him to give me the Isle of Wight. Besides--you _said_ you knew Grannie and Aunt Mary."

"Well, I happen to be quite a safe person, so you're all right this time, but it wouldn't _always_ do, you know," and the stranger gave his head a warning shake. "You are exceedingly kind. I only fear it would be rather a heavy job for you."

But this the boys denied strenuously. "If we stick, one of us will go and collect young Simpson and the other will watch the bike; but we'll be as right as rain--and we'd better hurry up." d.i.c.k left the trap as he spoke by the simple means of dropping over the side, and Jerry followed his example.

"I had better give you my name for Mr.--Simpson, did you say?--Major Campbell--Hugh Campbell."

There was a dead silence. If the stranger had said "George the Fifth of England" he could not have produced more effect. All three stared at him with their mouths open. "What's the matter with that?" he asked. "It's a very respectable name, and it really does belong to me. Perhaps I should give you my card." He put his hand in his breastpocket.

"Oh no," Mollie said rather breathlessly. "No--please don't mind-- it's quite all right, only--you look so young."

"So _what_?" exclaimed Major Campbell, standing stock still with his hand in his pocket.