Plot introduction:

The natural history museum is by no means boring, but its collection is amazing: there are prehistoric creatures with ferocious eyes, fierce ancient warriors, ethnic groups that have long since disappeared, animals in the African jungle and legendary heroes in history. These are all solidified in an instant, and no matter how time passes, they will not change.

Larry (Ben Stiller), an unfortunate dreamer, has many unattainable dreams. Larry believes that one day he can make amazing achievements. Of course, all this is just a dream. What is before us now is that he must find a job before Christmas. Otherwise, his youngest son will be raised by his ex-wife. Larry didn't want to disappoint his son, so he got a job as a night guard at the new york Museum of Natural History.

On the first night of work, he was left alone in an unusually quiet and huge museum with a huge flashlight and a detailed instruction manual. The old night watchman of the museum told Larry that his task was to "make sure that nothing can enter or leave the museum at night". Larry thinks the night watchman is crazy. Is there anything alive in the whole museum except him?

Wait! What's that noise? To Larry's disbelief, those prehistoric creatures and characters who only lived in storybooks came alive one by one! They surrounded him and everywhere they went was chaos: Tyrannosaurus Rex and Xiongnu smashed the marble wall of the museum; Lions and monkeys foraged around and took a fancy to precious and fragile exhibits; A three-inch cowboy kidnapped Larry and put him on a model railroad track. Indian soldiers threw spears at Larry ... Larry was at a loss and didn't know how to get the museum back to normal. Every night, these live models will torture Larry to death. During the day, people don't believe what Larry described and think he is mentally ill.

Larry racked his brains to find a memorial statue in the museum-former American President Roosevelt (robin williams) to help him survive this fright night. Facing the danger of losing his job and disappointing his son again, Larry is determined to win the battle to save the museum, hoping to be a brave and adventurous father. Isn't he waiting for this moment, for something important to happen for a long time? Now, the opportunity has finally come!