"It's on the coast, just down below where we live," was the answer.
"Then we can write and tell Mr. Ravenwood of Sea Gate that we have his box that was washed ashore," went on Harry's mother. "But we must get it higher up on the beach or it will wash away again. I wonder——"
But she suddenly stopped, for Sue gave a cry of alarm and pointed toward shore.
"Oh, look!" exclaimed the little girl. "Look!"
CHAPTER XXII
THE SURPRISING LETTER
Mrs. Slater was so interested in looking at the strange box which had been washed up on shore, and was thinking so deeply about the name of Frank Ravenwood which Bunny spelled for her that, for the moment, she did not quite understand what Sue meant.
"What is it, Sue?" she asked the little girl, for Sue kept on pointing toward something behind Mrs. Slater.
"The tide!" exclaimed Bunny's sister. "The tide's coming up and it's washing over the sand and we're on an island! We can't get back lessen we wade!"