Sam collected those Arrow once again using his telepathy. Actually he could use those Arrow as weapons while using his telepathy but it won't be that much powerful when he will use those Arrow using his bow. Because of this, he use Arrow with his bow. But that does not mean that he did not use his telepathy.
After killing those zombies Sam was now resting on the top of that building. You can say that he killed all those zombies easily because those zombies wear E-grade or D-grade. But here was the main question: how the hell did these zombies suddenly appear? He didn't know anything about this but one thing he was sure of was that most likely those zombies were the Warriors who lived here previously. Suddenly a question came to his mind,
'What happened to my family and friends? Did they also become zombies?'