In a small American town, veterinarian Andrew McDewey lives. He treats not only dogs and cats, but also livestock from surrounding farms, and is also a veterinarian in the area. Dr. McDewey is known as an honest but tough person: he ruthlessly euthanizes old animals and refuses to treat non-domestic animals.

Six years ago, his wife, Anne, died, cheerful, red as a copper pan and singing all the time. She contracted a disease from a parrot and died. Since then, the doctor’s heart has been petrified, and he vowed that there will be no more animals in his house.

Only love for the seven-year-old daughter Mary lives in him. Having lost his mother, she does not let her cat get Thomasina out of her hands. She pours out her soul, takes her to school with her, sets her at the table next to her. Thomasina doesn't like it that much. The cat was first called Thomas, but then they realized that this was not a cat, and was called Thomasina. Andrew does not like Thomasina and is very jealous of her daughter. Thomasina is dirty as best she can, but the vet suffers.

One day, a boy, Jordi McNab, brings a frog with a broken paw to the doctor, but he flatly refuses to treat it. Then Jordy takes the frog to the Red Witch, nicknamed Mad Lori. The witch lives in a dark forest and heals animals. Overcoming fear, Jordi comes for help. In the witch's house, he sees a pretty girl who sings loudly. Deer, cats and dogs come to her, and she feeds them. The girl agrees to cure the frog.

Dr. McDewey's friend, Priest Angus Peddy, loves his pug very much and overfeeds it with sweets. Between friends a dispute ensues. The doctor loved his wife, who died, and in order to love the animals, these loafers, he must spend his heart on them, which will soon not be enough. The priest does not agree: you need to love all living creatures.

Once, being on Mary’s shoulder, Thomasina unsuccessfully jumps and hits her head. Seeing that the cat is barely moving its paws, Mary brings her to her father in the hospital, where she is forbidden to appear: after the death of his wife, the doctor is afraid that Mary will be infected by animals. At this time, priest Peddy arrives with a blind man, whose car was driven by a guide dog. The dog needs an emergency operation. The doctor, not believing in success, wants to euthanize the animal. But the priest insists that it is necessary to save the man his eyes, citing God's commandments as evidence. Despite Mary's screams and threats that she would stop talking to her father, McDewey euthanizes Tomasina and does the operation for the dog.

While the father and his assistant are busy with the dog, Mary secretly takes away Thomasina’s still warm body. Mary’s friends arrange a funeral for the cat. In a mourning procession, they walk around the city and bury Tomasin in the forest, putting on her grave a plaque with the inscription "They brutally killed." Mad Lori sees this.

The operation is successful, and McDewey and Peddy are sent to please the blind man, but it is too late: he died. The veterinarian throws a rebuke to the priest: he saved the blind eyes, and God took him. The priest, in turn, reproaches the doctor for not trying to save Thomasina.

Mary refuses to talk with her father and walks in mourning clothes. The doctor brings her another cat, but with Merry begins a tantrum until her father takes the cat back. Priest Peddy is trying to reconcile her father and daughter, but the girl claims that her father died.

In the city, people do not approve of McDewey's act and begin to be afraid to treat his animals with him, fearing that he will put them to sleep. Also, rumors are circulating around the city that a woman lives a recluse in the forest, who speaks with angels and demons, understands the language of birds and treats animals. The doctor has a mysterious competitor. He decides to report to the police that an illiterate witch doctor takes bread from a graduate. Paddy dissuades a friend from touching the blessed.

Thomasina, under the name of the goddess Bast, enters the temple, a small house, where the priestess Mad Mad Lory. Now her father is Ra-Sun, and her mother is Huntor-Moon. The animals and birds in the temple do not accept the new inhabitant.

A wounded badger comes to Lori. While Laurie washes his wounds and thinks how to help, and Thomasina prays for his recovery, McDewey comes. Thomasina, now a goddess, is mortally afraid of a mortal and runs away from home.

McDewey did not expect the witch to be so tender and young, but he menacingly announces who he is. Rejoiced, Lori leads him to the badger. The doctor offers to euthanize the unfortunate animal, to which Lori replies that if God sent him here, then he believes in the doctor, and the animal must survive. The sorceress gives the doctor tools, and he does the badger operation, instead of using anesthesia, using the trust of the animal Lori. Lori leads McDewey to his hospital, where forest residents are waiting for help.

Instead of a treatment fee, Lori gives a soft wool scarf: when the wind blows, the doctor will be warm. The moved vet promises to return tomorrow to visit the badger. On the way home, McDewey reflects on God, on his love. At home, he has dinner with his daughter, puts her to bed, talks about the badger and Lori. It seems to him that his daughter’s attitude towards him has become better, although she still does not talk to him.

Thomasina swears revenge on McDewey. On a rainy night, when a storm broke out, Tomasina comes and claws against the glass in the doctor’s window. Startled with fear, he sees on every window, in every door of cats. Calling his favorite, Mary in one of his pajamas runs out into the street.

McDewey seeks help from Dr. Stratsi. For a month now the girl has not been talking with her father, and after she ran into the storm outside, her skin became wet. After examining the girl, Stratsi concludes that she is seriously ill and should be protected from shocks. McDewey begins to regret that he killed the cat, it would be better if she died her death.

To console himself, McDewey comes to Lori. Despite the fact that Tomasina is now the goddess of Talif, she is mortally afraid of her killer. But Laurie and McDewey now treat animals together.

Stratsi believes that Mary needs love, then the girl will recover. McDewey loves both Mary and Laurie, but for Mary he does not have enough tenderness, and Laurie is inferior, she speaks with spirits and gnomes. He goes to the priest for advice on what to do with Lori, who serves animals. The priest advises McDewey to get closer to Laurie and understand each other.

Mary's friends are calling for McDewey. The gypsies showed a performance and brutally beat the bear. Boys are asked to report animal cruelty to the police. One of the boys also calls for help Lori. Jealousy encompasses Thomasinu.

In a gypsy camp, McDewey meets Laurie. There is a fight between the doctor and the gypsies during which Laurie helps McDewey. Handling his wounds, Lori kisses the vet.

A dying Mary is waiting for McDewey at home - she does not want to live anymore. After spending the night near her daughter, in the morning McDewey goes to Lori for help. He rings her door, knocks, screams that he loves her and is ready to marry her, but Laurie does not open. In desperation, the doctor returns home to his still alive daughter. On the way, he sees a tablet on the grave of Thomasina. Falling to his knees, MacDewey asks God for forgiveness. Seeing this, Thomasina forgives him.

In the evening, in the storm, Dr. Laurie comes to Dr. McDewey. Taking Mary in her arms, she sings her a lullaby. Locked in Thomasina’s house, she feels that Mary is in trouble. She runs away from Lori’s house and comes under the girl’s window, despite the inclement weather. Father takes the wet cat and puts Mary in his arms. Mary forgives her father. Lori explains to the surprised McDewey that she pulled the cat out of the box and cried. Tears fell on Thomasina, and she woke up, she was alive. Thanks to anesthesia, paralysis went away.

Lori goes to the kitchen and thunders in pots. This is the order in the house when they stay forever.