A mysterious and terrifying trial suddenly begins, randomly pulling countless participants into dangerous instances. Han Beita is unfortunate enough to be selected, and receives no special talent whatsoever before being sent directly into the extremely difficult Midnight Hospital Ward. The ward is filled with hidden dangers, with numerous survival rules concealing deadly traps and all kinds of bizarre creatures lurking in the darkness, waiting for an opportunity to strike. Facing one crisis after another, Han Beita calmly observes his surroundings, continuously uncovers and breaks the traps hidden within the rules, and relies on his own abilities to fight off the dangers that come his way, doing everything he can to find a way to clear the instance.