A girl finds a purple boulder in the river bank, shining in the sun. She wants to turn it into a gift for her mother. So she makes herself a button out of tree bark. She places a tiny pebble in the middle that she can press to shrink the boulder down to pebble size. She presses the button and there morphs the boulder, leaving the treasured pebble. She bends down on all fours. She cups her hands into the water. She turns the pebble over and over again in her hand. Then she runs home to her mother and hands it to her without having to explain.