As a sniper, not only did Old Zhai have fantastic eyesight, but his hearing was also good.
In the past, he had not observed carefully, but after hearing some rumors, Old Zhai realized that Father Miao seemed to be limping. Even though Father Miao had tried his best to hide it, a careful observer would still notice it.
Old Zhai was sure that Father Miao had been fine the first time they had met. So, why was Father Miao limping now?
It turned out that a Japanese soldier had followed the bloody trail to the Miao family's house when Father Miao had brought Old Zhai at that time.
Thankfully, Father Miao was a smart young chap. Otherwise, Old Zhai would probably have had to face Father Miao's gravestone instead of seeing him limp around.
Because he had been afraid that the Japanese would find them, Father Miao had stripped Old Zhai of his clothes and had thrown them down the cliff after transporting him home behind his family's backs.