Professional cellist Mark Mathias accepts a position as “artist in residence” at Lamont University in New Mexico, and looks forward to using his free time to write music. On his first day, he meets Dr. Alex Bristow, and helps her capture the runaway chimpanzee she works with on a research project. As Mark watches her speak sign language with the ape, he becomes infatuated with her. Later, he sees Alex at a faculty party, and learns that she also teaches psychology courses. The awkward woman soon becomes uncomfortable with their small talk, and quickly flees. However, when her automobile fails to start, Alex is forced to accept a ride home from Mark. On the way, they retrieve “Michael,” the chimpanzee, from his babysitter’s house, and Alex explains that she uses the primate to research “language acquisition.” The next day, Mark sits in on one of her courses, and invites her out for coffee afterward, but she declines. While Mark plays his cello at home, his neighbor, Coral Grable, and her mute daughter, Cleo, hear him playing through his opened door. Coral introduces herself, and helps herself to a glass of wine from Mark’s kitchen. Elsewhere, Alex appeals to Dr. Parrish for more project funding, but he refuses, insisting her work with the chimpanzee is an embarrassment to the department. Later, Alex takes out her frustration on Mark, and is rude to him when he greets her. With Mark’s gentle persistence, Alex shares her worries about her project. Mark’s longtime friend, Mel Gorsky, warns him not to allow Alex to distract him from his music writing, and refers to Mark’s history of trying to “rescue” troubled women to his own detriment. When Mark learns that Alex is taking the chimp to a nature preserve, he packs a picnic lunch and pretends to run into her there. As they enjoy the day together, Alex begins to relax around him. Later, she realizes she has romantic feelings for Mark, and goes to his house unannounced, to see him. However, his neighbors Coral and Cleo Grable are at his home while Mark goes to the store to help Coral, who has a broken leg. Alex leaves, wrongly believing that Mark is married and has a child, and he wonders why she begins treating him coldly. Mark becomes distracted, and can no longer write music. In time, he visits Alex and tries to express his feelings, but she cuts him off. However, overcome with desire, they share a passionate kiss. Later, when Alex drives by Mark’s home, she sees him again with Coral and Cleo Grable, and regrets kissing him. Mark becomes babysitter to both Cleo and Michael the chimp, and on a day when he has them together, the mute girl begins to learn sign language from the chimpanzee. Later, Coral is stunned to see her daughter communicating with signs. When the girl asks to visit Michael, Mark takes Cleo and Coral to the science laboratory. Alex sees the threesome, and again mistakes them for a family. Jealous, Alex insists they leave. However, she later makes a weak apology to Mark. After she rejects him yet again, Mark becomes frustrated with her confusing behavior, and tells her he is returning to New York. Soon after, Alex makes an important presentation to the American Science Foundation (ASF), but when Michael is uncooperative, Dr. Parrish uses the opportunity to appeal to the committee, suggesting they give Alex’s chimpanzee to him for his own research project. Alex is distraught that the presentation went poorly, and feels guilty after yelling at the chimpanzee. When Mark arrives to say goodbye, chaos ensues, as Michael escapes and runs into a crowd of locals celebrating a harvest festival. As Mark and Alex search for the ape in a hay bale maze, he learns that she believed he was a married man. He tells her she is mistaken, and insists they need to start communicating better. Alex begs him not to leave town. Afterward, Alex confronts her superior, Dr. Parrish, but he insults her and shoves her to the ground. Mark comes to her defense, punching Parrish in the face. When Coral and Cleo arrive at the festival, Michael the chimp runs to see the little girl. The ASF committee watches as Cleo and the chimpanzee speak sign language with each other, and decide to grant research funding to Alex. In time, Mark practices his cello in Alex’s home, and she kisses him.