But the boy's plan was not completed.
As he stood idly by the step-ladder, on the top of which was Dent washing away at the windows, with the pail of warm water beside him, Bob appeared to be toying with a bit of string.
"I don't s'pose you have any doughnuts left, Susan ?" he ventured rather wistfully.
Now Susan had not forgiven Bob for a little joke he had played on her some time before, so at his hint, to show her displeasure, she turned her back and did not answer.

This was just what Bob wanted.
Looking up to see that Dent was not observing him, he passed one end of the string about the step-ladder.

Tying it securely, he fastened the other end to Susan's apron strings in such a manner that it would not pull off.
"I'll wait for you out in the barn," he said to Dent when it became evident that Susan was not going to take the hint and get the doughnuts.

In fact, Bob, much as he liked them, would have been disappointed if she had gone in for some.

He wanted to get out of the way before a certain thing happened.
He strolled off, but instead of going to the barn he hid around the corner of the house.