Based on a story by Melville Baker and Jack Kirkland, in the famous zoo of Budapest an animal lover helps an orphan and a child and himself in attempts to escape at the zoo.
Zani (Gene Raymond) is the son of an animal lover who died when he was three. Veterinarian Dr. Grunbaum (O. P. Heggie) helped raise the orphan Zani at the zoo. Zani has become very skilled at taking care of animals and often helps the doctor with his work. Zani gets upset when Heinie (Paul Fix) abuses the animals, and he warns him not to throw cigarettes at the tiger. Zani steals a purse from a woman because he does not like people using the furs of animals. The woman complains to the director who orders Zani brought in and arrested for the theft. However. Dr. Grunbaum talks to Zani who promises he will not do it again. However, when a wealthy woman with a fox fur persuades her husband to try to buy the fox from the zoo so that she can have his fur to match hers, Zani steals her fur from her. Now the director really wants Zani arrested and orders a search for him.
On the same day girls from an orphanage are visiting the zoo under the authoritarian head mistress Miss Murst (Lucille Ward). Zani and other girls help Eve (Loretta Young) to escape so that she will not be bonded out to work for five years now that she is eighteen years old. One girl jumps from a bridge into a river, and in the commotion Eve gets away with a dress so that she can change out of her uniform.
About the same time the little boy Paul Vandor (Wally Albright) runs away from his governess Katrina so that he can ride an elephant.
At night while the zoo is closed, and the animals are more relaxed, Zani finds Eve and helps her to avoid being found. He urges her not to think but feel, but he does ask her what she thinks she will do. She suggests they could get married and live in a house together like normal people. Before going to get food, he asks if he could have kissed her; but she simply asks if he is coming back, and he says he is. He brings food and a monkey to accompany them. He has already suggested that Dr. Grunbaum use another chimpanzee to help the one who has pneumonia, and this was successful.
The director is concerned that an orphan, a child, and Zani are all missing, and he orders all the employees to conduct a thorough search from the north wall of the zoo. One employee finds Zani and dislikes Heinie, and so he lets Zani go. Heinie manages to lock up the employee in a cage. Later the child Paul finds him. The employee tells Paul how to open the cage door, but he accidentally opens the wrong cage, freeing the tiger. The tiger runs wild and arouses the lions and other animals who manage to break out of their cages. The doctor directs people to enclose the wild animals in the arena by using a large net and water cannons. Zani, who is so good with animals, helps to bring them back under control. He and Eve are thus found, and the boy is also rescued. The wealthy Mr. Vandor (Niles Welch) is so happy to get his son back that he persuades Miss Murst to bond her to his care for five years. However, he says that Eve and Zani are getting married tomorrow, and they are going to live in a cottage on his estate and take care of his animals.
This outstanding animal picture portrays an extraordinary man who can communicate well with animals by using love and sensitivity. The natural lives of the animals are contrasted to the rigid discipline of the orphanage that keeps the girls in uniforms in a severely regimented life. Also the zoo with its cages shows how ruthless humans confine animals for their own selfish purposes.