Benjamin has lost his wife. In a bid to start his life over, he purchases a large house that has a zoo. This is welcome news for his daughter, but his son is not happy about it. The zoo is need of renovation and Benjamin sets about the work with the head keeper, Kelly, and the rest of the zoo staff. But, the zoo soon runs into financial trouble. The staff must get the zoo back to its former glory, pass a zoo inspection, and get it back open to the public.
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. Larry tries desperately to keep the museum under control, but he's fighting a losing battle until President Teddy Roosevelt comes to the rescue.
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.