This was the only disagreement we had all summer:  Aggie’s refusing to speak to Tish that entire day.  She said Mr. McDonald had seen her head and thought it was some sort of swimming animal, and had shot at her.

Mr. McDonald said afterward he knew her all the time, and was uncertain whether she was taking a cure for something or was trying to commit suicide.  He said he spent a wretched morning.  At five o’clock that evening we began to hear a curious tapping noise from the spy’s island.  It would last for a time, stop, and go on.

Hutchins said it was woodpeckers; but Tish looked at me significantly.

“Wireless!” she said.  “What did I tell you?”

That decided her next move, for that evening she put some tea and canned corn and a rubber blanket into the canoe; and in fear and trembling I went with her.

“It’s going to rain, Lizzie,” she said, “and after all, that detective may be surly; but he’s doing his duty by his country.  It’s just as heroic to follow a spy up here, and starve to death watching him, as it is to storm a trench—­and less showy.  And I’ve something to tell him.”

The canoe tilted just then, and only by heroic effort, were we able to calm it.

“Then why not go comfortably in the motor boat?”

Tish stopped, her paddle in the air.  “Because I can’t make that dratted engine go,” she said, “and because I believe Hutchins would drown us all before she’d take any help to him.  It’s my belief that she’s known him somewhere.  I’ve seen her sit on a rock and look across at him with murder in her eyes.”

A little wind had come up, and the wretched canoe was leaking, the chewing gum having come out.  Tish was paddling; so I was compelled to sit over the aperture, thus preventing water from coming in.  Despite my best efforts, however, about three inches seeped in and washed about me.  It was quite uncomfortable.

The red-haired man was asleep when we landed.  He had hung the comfort over a branch, like a tent, and built a fire at the end of it.  He had his overcoat on, buttoned to the chin, and his head was on his suit-case.  He sat up and looked at us, blinking.

“We’ve brought you some tea and some canned corn,” Tish said; “and a rubber blanket.  It’s going to rain.”

He slid out of the tent, feet first, and got up; but when he tried to speak he sneezed.  He had a terrible cold.

“I might as well say at once,” Tish went on, “that we know why you are here—­”

“The deuce you do!” he said hoarsely.

“We do not particularly care about you, especially since the way you acted to a friendly and innocent cat—­one can always judge a man by the way he treats dumb animals; but we sympathize with your errand.  We’ll even help if we can.”

“Then the—­the person in question has confided in you?”

“Not at all,” said Tish loftily.  “I hope we can put two and two together.  Have you got a revolver?”