When Reborn infiltrated the Estraneo base, his mission was simple. Find and kill #TSC-027. But when Reborn finds out that #TSC-027 is nothing but a scared little girl, he decides to let her live. But you see #TSC-027 wasn't just any experiments. She was raised to be an assassin. She was raised to be undefeated. And for some reason, she possessed the blood of Vongola. Just who was this girl that Reborn had set free?