"I—I don't know," answered Mun Bun. "I guess somebody must have poured more water in the river."
"Lessen maybe it rained," suggested Margy. "Don't you know how Rainbow River gets bigger when it rains?"
"It didn't rain," said Mun Bun, "or we'd be wet on our backs."
"No, I guess it didn't rain," agreed Margy. Then she cried: "Oh, look, Mun Bun! Our island's getting awful little! It only sticks out of the water hardly any now! Look!"
Mun Bun turned and looked behind him. As his sister had said, the island was very much smaller.
"What—what makes it?" asked Margy.
"I—I don't know," answered Mun Bun. "But it is getting littler, just like when you keep on sucking a lollypop."
And that is just what the island was doing. What Margy and Mun Bun did not know was that the tide had turned, that it was rising, and that it would soon not only make their island much smaller, but would cover it from sight, leaving no island at all!
"Oh, the water's getting deeper," said Margy, as she took another step and found it coming over her little knees. "What are we going to do, Mun Bun?"
"I—I guess we must go back to the middle of the island and stay there," said her brother.