The story of the one and only Ivan is placed at the Exit 8 Big Top Mall by the Video Arcade. Ivan, the Silverback Gorilla, has lived in captivity at the Big Top Mall for 9,876 days by his own tally. He lives in his domain, and is generally content with his life. He watches television, eats bananas, and makes artwork that is sold by the owner. Along with Ivan, Stella, an elephant, and Bob, a stray dog, live at the mall. Stella is an older elephant who has a chronic injury in one leg and regularly performs in the daily shows. Unlike Ivan, Stella has a long memory and can remember living in other places, like the circus where she was taught many of her tricks. However, Stella wanted to live in a zoo, because they have much wider spaces for their domains. Stella believes that good zoos are how humans make amends.
When Ruby, a baby elephant, is brought to the Big Top Mall to live with Stella and learn new tricks, things begin to change. Stella's old injury causes her to get sick. Just before Stella succumbs to her illness and passes away, she asks Ivan to take care of Ruby and find her a better place. Ivan promises he will take care of Ruby, even though he does not know how he will manage to do it.
After Stella's death, Ivan begins to remember his life before the Big Top Mall and what it was like to have freedom if only to have stories to tell to Ruby. While Mack, the owner of the Big Top Mall is trying to train Ruby to do tricks, Ivan witnessed first-hand the abuse to which she is subjected and starts to decide how to keep his promise to Stella.
When Julia, the custodian George's daughter, gives Ivan some finger paints, he begins to get an idea of how to help Ruby. He also changes his opinion of the Big Top Mall. He no longer thinks of his area as his domain but as a cage.
Ivan uses his art to make a large picture of the word "home". After Julia puts the letters together and discovers what Ivan is trying to convey, George and Julia help him by putting it on the billboard outside of the Big Top Mall. When people see the new signs, they begin to protest the treatment of the animals. Investigators are sent to the Big Top Mall and eventually, it is closed down. Ivan, Ruby, and the other animals are taken away to a zoo. Ivan lives in a white box for a while, only getting occasional visits to the zoo so that he can get adjusted to being a wild gorilla, but afterward he starts to live with his new gorilla family at the zoo. He later discovers Bob had become Julia's pet, and that he and Ruby had been both adopted by the same zoo, where they begin adapting to their new habitats and the other animals they now live with.
