A scientist lives with his daughter on a isolated island in the South Pacific. Abigail Breslin plays the lead character Nim. She lives with her father Jack (played by Gerard Butler), who is a microbiologist studying species of protozoa in the South Pacific Ocean. They have an idyllic life, except the island has a volcano. Nim passes her time reading books about a world-class adventurer named Alex Rover and playing with her pets, which include a sea lion, a pelican, a turtle, and a lizard. Jack gets the opportunity to capture a new species of luminescent protozoa. He invites Nim to go with him for the two-day sea trip. Nim asks her father if she can please stay on the island because her turtle is about to lay eggs and if she does not watch them and protect them, they will be eaten. Her father reluctantly agrees because the island is usually safe and Nim knows how to take care of herself.
While Jack is away, Nim reads the emails coming to him. An email comes from the author of the Alex Rover books. These are Nim and Jack's favorite books. The author Alexandra Rover (played by Jodie Foster) lives in San Francisco. She goes by the nickname "Alex" and the main character in her books is named the same. He is the adventure hero Alex Rover. Nim thinks Alex the author is the same as Alex the character in the books. Nim and Alex strike up a friendship through the emails. Nim tells Alex she is the assistant to the scientist Jack and they are doing research on a secret island in the South Pacific. Nim agrees to help Alex with the writing of the adventure book she is working to try to finish. Alexandra Rover has agoraphobia. She is so terrified of going outside; she is not even able to go out a few steps to retrieve the mail. She is also afraid of germs and orders many bottles of hand-sanitizer to be delivered by the pharmacy to her front door. The only thing she eats is Progresso soup. Alexandra Rover is the exact opposite of the character in her books, Alex Rover. The character Alex appears to Alexandra as a hallucination. He is not afraid of anything.
A cruise ship appears near Nim's Island. It is called the Buccaneer. This ship has the same name as one, which caused her mother to be lost at sea, when Nim was a little girl. Nim's father often tells her the story of how her mother was chasing the gigantic blue whale, when the Buccaneer ship frightened the whale causing her mother to fall in the ocean and be swallowed by the whale. Nim considers the Buccaneer ship very evil. An advance landing party comes ashore to check out what they think is an uninhabited island, which will be good for tourists. Nim, who hides in the jungle nearby, overhears them say they plan to invade the island. Many tourists are brought onshore. Nim frightens them off the island by launching lizards on them with large slingshots and by making the volcano emit smoke. One of the boys sees her but no one believes him.
Nim tells Alex by email she is all alone and her father is missing past the time he said he would return. Nim asks Alex to come help her. Alexandra the writer has an imaginary debate with the action character of Alex Rover. The character convinces her to leave the comfort of her place in San Francisco, and travel half way around the world to help the little girl. Alexandra is terrified of just about everything but she forces herself to go. She is afraid of flying, so she takes many motion sickness pills making herself drowsy enough to pass out. When she arrives in the South Pacific, she must take a small plane, a boat, and a helicopter to get to Nim's Island. There is a sudden terrible storm. The house where Nim lives is ruined by the hurricane winds and rain. Alex is in the helicopter, which is forced to land on the cruise ship Buccaneer. Alex tries to convince the boat's captain to take her to the island because a little girl is in danger, but the captain says they were just there and did not see any little girl. The boy tells Alexandra he saw the girl. Alexandra steals a lifeboat and rows towards the island in the middle of the huge storm. Jack's boat is badly damaged and his communications satellite disk is lost so he has no way to tell nim what happened. In addition, his boat starts to leak.
After the storm clears Jack's leaking boat is surrounded by sharks. Nim's pet pelican finds him. The bird flies to the island and returns with some tools, which help Jack to make repairs. Alexandra gets near to shore. Nim sees her. Thinking it is her father, Nim rides her sea lion to swim to the rescue. Nim is disappointed when she pulls the woman out of the water to keep her from drowning, especially when the woman tells her she is Alex Rover. Nim is expecting the action hero man, the character of Alex Rover to help her, not some woman who needs to be rescued. Nim breaks down and cries. Her father has been gone too long. Nim tells her if her father were alive, he would be home by now. Alexandra, having completely overcome all of her fears, promises her she will stay with her, and the little girl will never be alone. When all seems lost, the father does make it back to the island on a makeshift raft. Nim is so happy to see him. Jack is surprised to see a woman, especially one he is attracted to, there on the island with Nim. Alexandra and Jack immediately hit it off and in the end, they all walk down the beach together holding hands.
Best part of story, including ending:
The theme of this film is an exciting idea about living on a remote island that is unspoiled, in a place where no one else knows about.
Best scene in story:
I like the scene when Nim sends the lizards flying in the air onto the tourists on the beach. The closeups of the lizards coming down with evil looks on their faces, and the reactions of the tourists are hilarious.
Opinion about the main character:
Nim lives in fantasy world of make believe when she read books, but also in a kind of fantasy world in real life on a tropical paradise, which others could only dream of, so it is nice to see how the two combine with each other and make a happy ending.