The One and Only Family is the fourth book in the One and Only series. All four books follow Ivan and his best friends, Bob and Ruby, as they navigate what it means to be an animal in a world run by humans. The documentary and Ivan’s internal monologue from The One and Only Family recall events from the first book in the series, The One and Only Ivan (2012). Captive in the zoo arcade, a younger Ivan struggles with the pain of being isolated from his peers and poor treatment from humans who view him as little more than a money-making attraction. Through the relationships he builds with Bob and Ruby, as well as the girl who eventually adopts Bob, Ivan learns the importance of friendship and the power of trust, even in the darkest times.

The importance of friendship is also explored in the second book, The One and Only Bob (2020). Narrated by Bob the dog, the book follows the friends on the search for Bob’s lost sister.