With a sinking heart, Jack often called to mind that this was his last term at school. The little money that his father had left was not enough to warrant his continuing; he must now do something for his own support. He resolved, therefore, to make the most of his time under Mr. Williams.

When Pewee, Riley, and Ben Berry got through with their punishment, they sought some way of revenging themselves on the master for punishing them, and on Jack for doing better than they had done, and thus escaping punishment. It was a sore thing with them that Jack had led all the school his way, so that, instead of the whole herd following King Pewee and Prime Minister Riley into rebellion, they now “knuckled down to the master,” as Riley called it, under the lead of Jack, and they even dared to laugh slyly at the inseparable “triplets.”

The first aim of Pewee and company was to get the better of the master. They boasted to Jack and Bob that they would fix Mr. Williams some time, and gave out to the other boys that they knew where the master spent his evenings, and they knew how to fix him.

When Jack heard of this, he understood it. The teacher had a habit of spending an evening, now and then, at Dr. Lanham’s, and the boys no doubt intended to play a prank on him in going or coming. There being now no moonlight, the village streets were very dark, and there was every opportunity for a trick. Riley’s father’s house stood next on the street to Dr. Lanham’s; the lots were divided by an alley. This gave the triplets a good chance to carry out their designs.

But Bob Holliday and Jack, good friends to the teacher, thought that it would be fun to watch the conspirators and defeat them. So, when they saw Mr. Williams going to Dr. Lanham’s, they stationed themselves in the dark alley on the side of the street opposite to Riley’s and took observations. Mr. Williams had a habit of leaving Dr. Lanham’s at exactly nine o’clock, and so, just before nine, the three came out of Riley’s yard, and proceeded in the darkness to the fence of Lanham’s dooryard.

Getting the trunk of one of the large shade-trees between him and the plotters, Jack crept up close enough to guess what they were doing and to overhear their conversation. Then he came back to Bob.

“They are tying a string across the sidewalk on Lanham’s side of the alley, I believe,” whispered Jack, “so as to throw Mr. Williams head foremost into that mud-hole at the mouth of the alley.”

By this time, the three boys had finished their arrangements and retreated through the gate into the porch of the Riley house, whence they might keep a lookout for the catastrophe.

“I’m going to cut that string where it goes around the tree,” said Bob, and he crouched low on the ground, got the trunk of the tree between him and the Riley house, and crept slowly across the street.

“I’ll capture the string,” said Jack, walking off to the next cross-street, then running around the block until he came to the back gate of Lanham’s yard, which he entered, running up the walk to the back door. His knock was answered by Mrs. Lanham.

“Why, Jack, what’s the matter?” she asked, seeing him at the kitchen door, breathless.

“I want to see Susan, please,” he said, “and tell Mr. Williams not to go yet a minute.”

“Here’s a mystery,” said Mrs. Lanham, returning to the sitting-room, where the teacher was just rising to say good-night. “Here’s Jack Dudley, at the back door, out of breath, asking for Susan, and wishing Mr. Williams not to leave the house yet.”

Susan ran to the back door.

“Susan,” said Jack, “the triplets have tied a string from the corner of your fence to the locust-tree, and they’re watching from Riley’s porch to see Mr. Williams fall into the mud-hole. Bob is cutting the string at the tree, and I want you to go down along the fence and untie it and bring it in. They will not suspect you if they see you.”

“I don’t care if they do,” said Susan, and she glided out to the cross-fence which ran along the alley, followed it to the front and untied the string, fetching it back with her. When she got back to the kitchen door she heard Jack closing the alley gate. He had run off to join Bob, leaving the string in Susan’s hands.

Dr. Lanham and the master had a good laugh over the captured string, which was made of Pewee’s and Riley’s top-strings, tied together.

The triplets did not see Susan go to the fence. They were too intent on what was to happen to Mr. Williams. When, at length, he came along safely through the darkness, they were bewildered.

“You didn’t tie that string well in the middle,” growled Pewee at Riley.

“Yes, I did,” said Riley. “He must have stepped over.”

“Step over a string a foot high, when he didn’t know it was there?” said Pewee.

“Let’s go and get the string,” said Ben Berry.

So out of the gate they sallied, and quickly reached the place where the string ought to have been.

“I can’t find this end,” whispered Pewee by the fence.

“The string’s gone!” broke out Riley, after feeling up and down the tree for some half a minute.

What could have become of it? They had been so near the sidewalk all the time that no one could have passed without their seeing him.

The next day, at noon-time, when Susan Lanham brought out her lunch, it was tied with Pewee’s new top-string,—the best one in the school.

“That’s a very nice string,” said Susan.

“It’s just like Pewee’s top-string,” cried Harry Weathervane.

“Is it yours, Pewee?” said Susan, in her sweetest tones.

“No,” said the king, with his head down; “mine’s at home.”

“I found this one, last night,” said Susan.

And all the school knew that she was tormenting Pewee, although they could not guess how she had got his top-string. After a while, she made a dive into her pocket, and brought out another string.

“Oh,” cried Johnny Meline, “where did you get that?”

“I found it.”

“That’s Will Riley’s top-string,” said Johnny. “It was mine. He cheated me out of it by trading an old top that wouldn’t spin.”

“That’s the way you get your top-strings, is it, Will? Is this yours?” asked the tormenting Susan.

“No, it isn’t.”

“Of course it isn’t yours. You don’t tie top-strings across the sidewalk at night. You’re a gentleman, you are! Come, Johnny, this string doesn’t belong to anybody; I’ll trade with you for that old top that Will gave you for a good string. I want something to remember honest Will Riley by.”

Johnny gladly pocketed the string, and Susan carried off the shabby top, to the great amusement of the school, who now began to understand how she had come by the two top-strings.