"Add the numbers!" said Tish. "Thirty-one tons, perhaps, of dynamite!

And that's only part," said Tish. "Here's the most d.a.m.ning thing of all--a note to his accomplice!"

"d.a.m.ning" is here used in the sense of condemnatory. We are none of us addicted to profanity.

We read the other paper, which had been in a sealed envelope, but without superscription. It is before me as I write, and I am copying it exactly:--

I shall have to see you. I'm going crazy! Don't you realize that this is a matter of life and death to me? Come to Island Eleven to-night, won't you? And give me a chance to talk, anyhow. Something has got to be done and done soon. I'm desperate!

Aggie sneezed three times in sheer excitement; for anyone can see how absolutely incriminating the letter was. It was not signed, but it was in the same writing as the list.

Tish, who knows something about everything, said the writing denoted an unscrupulous and violent nature.

"The _y_ is especially vicious," she said. "I wouldn't trust a man who made a _y_ like that to carry a sick child to the doctor!"

The thing, of course, was to decide at once what measures to take. The boat would not come again for two days, and to send a letter by it to the town marshal or sheriff, or whatever the official is in Canada who takes charge of spies, would be another loss of time.

"Just one thing," said Tish. "I'll plan this out and find some way to deal with the wretch; but I wouldn't say anything to Hutchins. She's a nice little thing, though she is a fool about a motor boat. There's no case in scaring her."

For some reason or other, however, Hutchins was out of spirits that night.

"I hope you're not sick, Hutchins?" said Tish.

"No, indeed, Miss Tish."

"You're not eating your fish."

"I'm sick of fish," she said calmly. "I've eaten so much fish that when I see a hook I have a mad desire to go and hang myself on it."

"Fish," said Tish grimly, "is good for the brain. I do not care to boast, but never has my mind been so clear as it is to-night."

Now certainly, though Tish's tone was severe, there was nothing in it to hurt the girl; but she got up from the cracker box on which she was sitting, with her eyes filled with tears.

"Don't mind me. I'm a silly fool," she said; and went down to the river and stood looking out over it.

It quite spoiled our evening. Aggie made her a hot lemonade and, I believe, talked to her about Mr. Wiggins, and how, when he was living, she had had fits of weeping without apparent cause. But if the girl was in love, as we surmised, she said nothing about it. She insisted that it was too much fish and nervous strain about the Mebbe.

"I never know," she said, "when we start out whether we're going to get back or be marooned and starve to death on some island."

Tish said afterward that her subconscious self must have taken the word "marooned" and played with it; for in ten minutes or so her plan popped into her head.

"'Full-panoplied from the head of Jove,' Lizzie," she said. "Really, it is not necessary to think if one only has faith. The supermind does it all without effort. I do not dislike the young man; but I must do my duty."

Tish's plan was simplicity itself. We were to steal his canoe.

"Then we'll have him," she finished. "The current's too strong there for him to swim to the mainland."

"He might try it and drown," Aggie objected. "Spy or no spy, he's somebody's son."

"War is no time to be chicken-hearted," Tish replied.

I confess I ate little all that day. At noon Mr. McDonald came and borrowed two eggs from us.

"I've sent over to a store across country, by my Indian guide, philosopher, and friend," he said, "for some things I needed; but I dare say he's reading Byron somewhere and has forgotten it."

"Guide, philosopher, and friend!" I caught Tish's eye. McDonald had written the Updike letter! McDonald had meant to use our respectability to take him across the border!

We gave him the eggs, but Tish said afterward she was not deceived for a moment.

"The Indian has told him," she said, "and he's allaying our suspicions.

Oh, he's clever enough! 'Know the Indian mind and my own!'" she quoted from the Updike letter. "'I know Canada thoroughly.' 'My object is not money.' I should think not!"

Tish stole the green canoe that night. She put on the life preserver and we tied the end of the rope that Aggie had let slip to the canoe. The life-preserver made it difficult to paddle, Tish said, but she felt more secure. If she struck a rock and upset, at least she would not drown; and we could start after her at dawn with the Mebbe.

"I'll be somewhere down the river," she said, "and safe enough, most likely, unless there are falls."

Hutchins watched in a puzzled way, for Tish did not leave until dusk.

"You'd better let me follow you with the launch, Miss Tish," she said.

"Just remember that if the canoe sinks you're tied to it."

"I'm on serious business to-night, Hutchins," Tish said ominously. "You are young, and I refuse to trouble your young mind; but your ears are sharp. If you hear any shooting, get the boat and follow me."

The mention of shooting made me very nervous. We watched Tish as long as we could see her; then we returned to the tent, and Aggie and I crocheted by the hanging lantern. Two hours went by. At eleven o'clock Tish had not returned and Hutchins was in the motor boat, getting it ready to start.

"I like courage, Miss Lizzie," she said to me; "but this thing of elderly women, with some sort of bug, starting out at night in canoes is too strong for me. Either she's going to stay in at night or I'm going home."

"Elderly nothing!" I said, with some spirit. "She is in the prime of life. Please remember, Hutchins, that you are speaking of your employer.

Miss Tish has no bug, as you call it."

"Oh, she's rational enough," Hutchins retorted: "but she is a woman of one idea and that sort of person is dangerous."

I was breathless at her audacity.

"Come now, Miss Lizzie," she said, "how can I help when I don't know what is being done? I've done my best up here to keep you comfortable and restrain Miss Tish's recklessness; but I ought to know something."

She was right; and, Tish or no Tish, then and there I told her. She was more than astonished. She sat in the motor boat, with a lantern at her feet, and listened.

"I see," she said slowly. "So the--so Mr. McDonald is a spy and has sent for dynamite to destroy the railroad! And--and the red-haired man is a detective! How do you know he is a detective?"

I told her then about the note we had picked up from beside her in the train, and because she was so much interested she really seemed quite thrilled. I brought the cipher grocery list and the other note down to her.

"It's quite convincing, isn't it?" she said. "And--and exciting! I don't know when I've been so excited."

She really was. Her cheeks were flushed. She looked exceedingly pretty.

"The thing to do," she said, "is to teach him a lesson. He's young. He mayn't always have had to stoop to such--such criminality. If we can scare him thoroughly, it might do him a lot of good."