He saw they were three girls, and he instantly recognized one of them as Inza.

The others were Belinda Snodd and one of the village girls, with whom Frank was slightly acquainted, Mabel Blossom, generally known as May Blossom.
"They are coming here!" exclaimed Frank.

"They must not see me!" He arose hastily, and scurried away into the grove, and he did not stop till he had reached the shore.

There he sat down amid some rocks, and remained a long time, as it seemed to him.
But he could not resist the temptation to steal back and see if the girls were still in the grove.

He finally arose and did so.
As he passed through the grove and came out near the old picnic-ground, he suddenly halted and stepped behind a tree, for he had come upon two persons in earnest conversation.
They were Inza Burrage and Leslie Gage!.