"Your pockets are filled with stones, and they now find their purpose. With every distance you cover, you toss a stone behind you to attract any presence that might be there in the darkness..."
Tesla didn't say "next," implying that it wasn't yet Lu Li's turn to act. But at this moment, Lu Li spoke up, "I'm throwing the stones so that her sister can hear."
"... As well as to let her sister hear. If she's still alive, she hasn't eaten for over a dozen days and would easily miss any rescue under the circumstances of weakness."
"You maintain the frequency of tossing stones as you make your way along the right wall in the dim ruins. The palm of your hand touching the wall is cold and numb, and the number of stones in your pocket begins to decrease. You've forgotten how many times you've turned, but thankfully, by always keeping to the right, you haven't lost your way in the ruins. You can turn back anytime if you wish."