On a magical night at the American Museum of Natural History in New York, Larry Daley, the coolest night guard in history, discovers that the magic that brings the exhibits to life is starting to fade. After a series of peculiar and comedic events, he learns that the secret keeping it all going resides in an ancient artifact that not only made the magic possible but also needs an urgent "touch-up."
Under pressure, Larry embarks on an international adventure that takes him to London, where he reunites with a version of his imperial friend, Pharaoh Ahkmenrah, and his family. Together, they must solve the mystery threatening not only the museum's nighttime life but also their connection to history. As they travel through the iconic British Museum, they must deal with new characters, including London's night guard, and confront old enemies. Alongside the jokes and humor, Larry and his friends face moments of reflection on friendship and history.
The film blends action, comedy, and a touch of fantasy as both human characters and historical figures strive to keep the spark of the museum's magic alive. Amid laughter and life lessons, it reminds us that memories and connections are what truly bring our history to life.