The novel tells the coming-of-age story of Lin Chen, who leaves the battlefield behind for campus life and ultimately finds a place of peace in his heart. At 23, Lin Chen was a mercenary for the Westland Federation. He signed away his freedom to pay for his critically ill mother's treatment and spent five years facing life and death on the battlefield. After his mother dies, he returns home covered in scars and suffering from PTSD. As an older-than-usual repeat student, he enrolls at Donghai University, hoping to find a chance to “make it” in a peaceful world.
On campus, he hides his past and uses military thinking to handle his studies, start a business, and navigate relationships. Together with his three roommates, he forms the “Four Knights of Sunken Boat” and launches a secondhand book platform called Sunken Boat. He meets Gu Xiao, an art student whose paintings slowly soothe the shrapnel lodged in his soul. When the remnants of the Darkfire forces threaten everything he holds dear, Lin Chen has no choice but to return to the methods of the battlefield to protect his loved ones, his brothers, and his ideals.
Through Lin Chen's transformation from “killing tool” to “protector,” the story explores healing from trauma, identity, and emotional redemption. In the end, with Gu Xiao by his side and his brothers bound by their oath, he finds a shore of his own: not fame or success, but someone waiting for him and a home to return to.
