Right... since Kat was already in the lake she was ready. Stacking the stones the round one, the triangle, and the square stone on top. That way she could drop them right into the water. She got a good spot or in her opinion a good spot.

Drop goes the round stone. Counting out the seconds. She dropped the triangle stone. Then counting down to the thirty seconds, she dropped the last square stone into the lake.

Since she was out in the lake, wading she couldn't bring her book so she had plenty of time and focus to look at her ripples and decode the shapes. Then she would go and find out what there meaning was.