There are also altruistic people in a selfish world. ""There is nothing more precious than human life Right?" "Of course. But do you know what it means to save a person?" "What are you trying to say?" Team leader Lee Chaeyoung smiled when Taegun tilted his head. "If you save one person, you save that person's family." "Yes?" "If that person dies, what about the future of family and acquaintances?" Those few words changed Taegun's life. The day we live today is the tomorrow that someone who died yesterday longed for. What if you risk your life to save the lives of others and to continue the stories of their life? It is a reward that money can never buy. Call sign! It's a power that can move instinctively to the sound that is asking for saving life.