Yan Wan is an extremely ordinary person.
An ordinary family of three, ordinary looks, ordinary classmates, and slightly excellent grades.
She was supposed to be a normal person - until that day.
On July 18, 2039, a terrorist attack occurred at X High School. 326 Students were killed in explosions and shootings, and one person is missing.
She is the only person whose whereabouts are unknown - Yan Wan.