When the magic powers of The Tablet of Ahkmenrah begin to die out, Larry Daley spans the globe, uniting favorite and new characters while embarking on an epic quest to save the magic before it is gone forever.
Hapless museum night watchman Larry Daley must help his living, breathing exhibit friends out of a pickle now that they've been transferred to the archives at the Smithsonian Institution. Larry's (mis)adventures this time include close encounters with Amelia Earhart, Abe Lincoln and Ivan the Terrible.
In a gritty and alternate 1985, the glory days of costumed vigilantes have been brought to a close by a government crackdown. But after one of the masked veterans is brutally murdered, an investigation into the killer is initiated. The reunited heroes set out to prevent their own destruction, but in doing so they uncover a sinister plot that puts all of humanity in grave danger.
Chaos reigns at the natural history museum when night watchman Larry Daley accidentally stirs up an ancient curse, awakening Attila the Hun, an army of gladiators, a Tyrannosaurus rex and other exhibits.