Nigel (voice of TIM CURRY) and Marianne Thornberry (voice of JODI CARLISLE) have traveled the world with their kids, teenager Debbie (voice of DANIELLE HARRIS), 12-year-old Eliza (voice of LACEY CHABERT) and wild younger brother Donnie (voice of FLEA), making wildlife documentaries.
Now in the African savannah, along with Nigel's stuffy British parents, Radcliffe and Cordelia (voice of LYNN REDGRAVE), the family is preparing to travel to the Congo to see an elephant migration that will coincide with an eclipse.
That's exciting for Eliza as a spell cast on her by shaman Mnyambo (voice of KEVIN MICHAEL RICHARDSON) has enabled her to speak with all animals, including her best friend, Darwin (voice of TOM KANE), a proper sounding chimp. That gift, however, results in trouble when she goes off to play with several cubs belonging to Akela (voice of ALFRE WOODARD), a mother cheetah.
Before Eliza can do anything, poachers sweep down and seize one of the cubs, Tally (voice of KIMBERLY BROOKS). Despite her best efforts, Eliza can't rescue him and feels awful about what happened. Seeing that and fearing what the wild is doing to her granddaughter, Cordelia implores that Eliza be sent off to a London boarding school to receive a proper education and social training.
With Eliza and Darwin away, the rest of the family heads for the Congo, but it's not long before the two of them escape and make their way back to Africa where they run into Sloan (voice of RUPERT EVERETT) and Bree Blackburn (voice of MARISA TOMEI), the latter of whom claims to be a wildlife veterinarian.
As Eliza resumes her quest to find and rescue Tally, she eventually learns that the poachers are also headed for the elephant migration in the Congo. Racing against time and facing the threat of losing her gift should she tell anyone of it, she and the rest of the family do what they must to help each other and stop the poachers.