SKIPPING STONES
"I know stone," said Fíli, tossing his flawless rock so it skipped seven times before sinking.
Sigrid smiled, then began walking along the shore; and Fíli followed patiently for fifteen minutes, since she'd given him as much time to find his own perfect stone. He grinned confidently when she eventually chose a rather inferior rock; but when she tossed it, the stone skipped nine times before sliding into the water.
Because while Fili knew stone, Sigrid knew this lake and its currents; and so she won the bet, and for the next week, Fíli would be cooking dinner for her.