"Push the ring under the canvas. Then slip out at the back and join the others. When I see you with them I'll disappear. Go slow, and I'll catch you up."

"It's me," said a pale and obvious Mabel in the ear of Kathleen.

"He's got the ring; come on, before the crowd begins to scatter."

As they went out of the gate they heard a roar of surprise and annoyance rise from the crowd, and knew that this time Gerald really had disappeared.

They had gone a mile before they heard footsteps on the road, and looked back. No one was to be seen.

Next moment Gerald's voice spoke out of clear, empty-looking s.p.a.ce.

"Halloa!" it said gloomily.

"How horrid!" cried Mabel; "you did make me jump! Take the ring off; it makes me feel quite creepy, you being nothing but a voice."

"So did you us," said Jimmy.

"Don't take it off yet," said Kathleen, who was really rather thoughtful for her age, "because you're still blackleaded, I suppose, and you might be recognized, and eloped with by gypsies, so that you should go on doing conjuring for ever and ever."

"I should take it off," said Jimmy; "it's no use going about invisible, and people seeing us with Mabel and saying we've eloped with her."

"Yes," said Mabel impatiently, "that would be simply silly. And, besides, I want my ring."

"It's not yours any more than ours, anyhow," said Jimmy.

"Yes, it is," said Mabel.

"Oh, stow it!" said the weary voice of Gerald beside her. "What's the use of jawing?"

"I want the ring," said Mabel, rather mulishly.

"Want" the words came out of the still evening air "want must be your master. You can't have the ring. I can't get it off!"

The difficulty was not only that Gerald had got the ring on and couldn't get it off, and was therefore invisible, but that Mabel, who had been invisible and therefore possible to be smuggled into the house, was now plain to be seen and impossible for smuggling purposes.

The children would have not only to account for the apparent absence of one of themselves, but for the obvious presence of a perfect stranger.

"I can't go back to aunt. I can't and I won't," said Mabel firmly, "not if I was visible twenty times over."

"She'd smell a rat if you did," Gerald owned "about the motor-car, I mean, and the adopting lady. And what we're to say to Mademoiselle about you !" He tugged at the ring.

"Suppose you told the truth," said Mabel meaningly.

"She wouldn't believe it," said Cathy; "or, if she did, she'd go stark, staring, raving mad."

"No," said Gerald's voice, "we daren't tell her. But she's really rather decent. Let's ask her to let you stay the night because it's too late for you to get home."

"That's all right," said Jimmy, "but what about you?"

"I shall go to bed," said Gerald, "with a bad headache. Oh, that's not a lie! I've got one right enough. It's the sun, I think. I know blacklead attracts the concentration of the sun."

"More likely the pears and the gingerbread," said Jimmy unkindly.

"Well, let's get along. I wish it was me was invisible. I'd do something different from going to bed with a silly headache, I know that."

"What would you do?" asked the voice of Gerald just behind him.

"Do keep in one place, you silly cuckoo!" said Jimmy. "You make me feel all jumpy. He had indeed jumped rather violently. "Here, walk between Cathy and me.

"What would you do?" repeated Gerald, from that apparently unoccupied position.

"I'd be a burglar," said Jimmy.

Cathy and Mabel in one breath reminded him how wrong burgling was, and Jimmy replied:

"Well, then a detective."

"There's got to be something to detect before you can begin detectiving," said Mabel.

"Detectives don't always detect things," said Jimmy, very truly. "If I couldn't be any other kind I'd be a baffled detective. You could be one all right, and have no end of larks just the same. Why don't you do it?"

"It's exactly what I am going to do," said Gerald. "We'll go round by the police-station and see what they've got in the way of crimes."

They did, and read the notices on the board outside. Two dogs had been lost, a purse, and a portfolio of papers "of no value to any but the owner." Also Houghton Grange had been broken into and a quant.i.ty of silver plate stolen. "Twenty pounds reward offered for any information that may lead to the recovery of the missing property."

"That burglary's my lay," said Gerald; "I'll detect that. Here comes Johnson," he added; "he's going off duty. Ask him about it. The fell detective, being invisible, was unable to pump the constable, but the young brother of our hero made the inquiries in quite a creditable manner. Be creditable, Jimmy."

Jimmy hailed the constable.

"Halloa, Johnson!" he said.

And Johnson replied: "Halloa, young shaver!"

"Shaver yourself!" said Jimmy, but without malice.

"What are you doing this time of night?" the constable asked jocosely. "All the d.i.c.ky birds is gone to their little nesteses."

"We've been to the fair," said Kathleen. "There was a conjurer there. I wish you could have seen him."

"Heard about him," said Johnson; "all fake, you know. The quickness of the 'and deceives the hi."

Such is fame. Gerald, standing in the shadow, jingled the loose money in his pocket to console himself.

"What's that?" the policeman asked quickly.

"Our money jingling," said Jimmy, with perfect truth.

"It's well to be some people," Johnson remarked; "wish I'd got my pockets full to jingle with."

"Well, why haven't you?" asked Mabel. "Why don't you get that twenty pounds reward?"