"But what is it?" said Margy, puzzled. "It looks like a—a—grave."
Polly clutched her arm and Jess shrieked. Before their fascinated eyes the mound was sinking. It slumped in the middle, cracks appeared in the sand far behind it, and without a sound the mound caved in.
"Dig!" commanded Polly furiously. "Dig! Don't stand there and do nothing!"
SOME OLD FRIENDS
Polly was down on her knees, flinging handfuls of sand behind her with feverish energy.
"What's the matter?" Jess demanded. "What's underneath?"
Polly never stopped scooping up the sand.