I'm not sure as I haven't actually read the novel. But typically, in a sad story, there might be a protagonist who is at the center of the tragic events. It could be a character who has faced a lot of hardships in life.
One of the main themes could be loss. It might explore the loss of love, relationships, or hope. Maybe the characters in the novel experience a great sense of emptiness due to various forms of loss.
I'm not sure as the name of the novel doesn't give much clue about the characters directly. But they could be ordinary people facing extraordinary hardships.
The saddest story I've heard is about a little dog. It was abandoned by its owner at a very young age. It wandered the streets alone, cold and hungry, looking for a place to belong but always being chased away. Eventually, it died in a corner, with no one to care for it.
A really sad ghost story is about an old man who passed away suddenly in his old house. His ghost stays because he's worried about his dog that he left behind. The dog doesn't understand why its master is gone. The old man's ghost watches over the dog, but he can't interact with it. It's a story full of loneliness and love for a pet.
One of the saddest origin stories could be that of Batman. Bruce Wayne witnessed the murder of his parents when he was just a child. This tragic event in Crime Alley not only robbed him of his family but also set him on a path of vengeance and justice. He dedicated his life to fighting crime in Gotham, constantly haunted by the memory of that fateful night.
One of the saddest Roblox stories I've heard was about a young player who spent months building an amazing virtual world on Roblox. They were so proud of it and it was a place full of their creativity. But then, due to a glitch in the system, their world got deleted and all their hard work vanished. They were heartbroken as it was like losing a part of themselves.
One of the saddest mom stories I know is about a mom who lost her only son in a war. She had dedicated her whole life to raising him, with so many hopes and dreams pinned on him. After his death, she was left in a state of utter despair, just staring at his empty room every day, unable to move on from the grief.