Dr. Hugo Archibald bringt einen Schimpansen namens Jennie mit nach Hause. Vom ersten Tag an wird sie wie ein Familienmitglied behandelt. Besonders vom elfjährigen Andrew, der eine enge Freundschaft mit ihr aufbaut. Jennie lernt die Zeichensprache, spielt Baseball, liebt Comics und ist eine echte Vertraute für Andrew. Zusammen brechen sie in ein magisches Abenteuer auf.

Le docteur Hugo Archibat, un scientifique spécialiste des primates, ramène de l'un de ses voyages en Afrique une chimpanzé répondant au nom de Jennie. L'animal apprend bien vite le langage des signes...

Hugo Archibald is a doctor and brings home a wide variety of exotic animal species. The latest animal he brings home is a chimpanzee named Jennie. Dr. Archibald is not home very much, and Andrew feels he does not care about him. And Lea his wife does not want Jennie, and says she makes trouble. But the children take an instant liking to her. Jennie is unique in that she is learning to use and understand sign language. Jennie becomes an important part of Archibald family and Dr. Archibald's son, Andrew develops a close relationship with her. Jennie loves the things Andrew does, such as baseball and comic books. Jennie is also there for Andrew when he and his father disagree. A doctor Pamela Prentiss starts training with Jennie. She does not agree with the way Jennie is being cared for, and is seen as being rude to the Archibald family. She teaches Jennie sign language in a way that Jennie does not understand, but Lea finds a way she understands.

Il dottor Hugo Archibald è solito portare a casa alcuni esemplari di animali esotici e l"ultimo in ordine di tempo è uno scimpanzé di nome Jennie, che sta imparando il linguaggio dei segni. A passar molto tempo a stretto contatto con Jennie è Andrew, il piccolo figlio di Hugo, che con l'animale instaura un forte rapporto di amicizia.

Baseado no livro Jennie por Douglas Preston, o 'Jennie Project' conta a história de um chimpanzé chamado Jennie que tem a habilidade de usar e entender a linguagem de sinais. Quando o Dr. Hugo Archibald traz para casa o que há de mais recente em uma longa linha de criaturas, Jennie rapidamente se torna uma parte importante da família Archibald e, eventualmente, aproxima toda a família.