"I'll prove it to you" Nathan said to his Adventurer friends who gave him their full attention.
They remained silent after seeing his glare and serious look. Nathan looked around him with suspicion, ensuring no one was paying attention to them.
"Listen to me first. It's quite the story"
Nathan narrated his experience to his friends. How he joined a new party after his last one perished thanks to his usual methods. Marie, his girl, was the one who introduced him to them and so they decided to let him in.
They took a few quests together in order for them to trust him so he could be fully absorbed within their group. Since their party had no definite leader, it was rotated amongst them, depending on the quest.
The job in the Forest Of Monsters was one of the quests he decided to take in order to bond with them properly. He knew it would be dangerous, but it was in very pernicious situations that comradeship blossoms.