The film was based on Margery Sharp’s “The Rescuers” children’s novels, most notably, The Rescuers (1959) and Miss Bianca (1962). The film was four years in the making with the combined talents of 250 people, including 40 animators who produced approximately 330,000 drawings; there were 14 sequences with 1,039 separate scenes and 750 backgrounds.

Synopsis

The Rescuers begins when a young orphan named Penny throws a message in a bottle from an abandoned luxury river boat on which she is held a prisoner. The bottle washes up in America and is taken to the Rescue Aid Society, a UN-like group located in New York City consisting of representative mice from all over the world and dedicated to providing assistance to people in peril. The mice read the message inside and learn that Penny was kidnapped, but do not learn where she is. The compassionate Hungarian representative, Miss Bianca, volunteers to save the girl. The Chair of the society agrees, on the condition that Bianca chooses a partner for her safety. Of all the eager male delegates, she chooses Bernard, the janitor, for whom she has a soft spot. The two set out to the orphanage where Penny lived and there meet a local cat, Rufus, who has secretly retired from hunting mice. He tells them that Penny was a close friend of his, who despaired of being adopted by any family; that he had attempted to re-assure her; and that she is assumed to have fled of her own accord. The only alternative is to the effect that she was kidnapped by a mysterious, ill-meaning woman called Madame Medusa.

The mice then travel to Madame Medusa’s pawnshop. While they are searching for clues, they hear Medusa talking on the telephone to her assistant and partner, Mr. Snoops, whom she reprimands for being unable to find the “Devil’s Eye” Diamond and for failing to prevent Penny’s message being sent. Angrily, she tells Mr. Snoops that she will take “the next flight down to Devil’s Bayou” and leaves in her car. Bernard and Miss Bianca try to climb into her suitcase, but are thrown from it by Medusa’s reckless driving.

To reach the Bayou, the mice recruit the help of an albatross named Orville, who flies them to Devil’s Bayou. There, they are greeted by two muskrats named Ellie Mae and Luke and a dragonfly named Evinrude, who loathe Medusa for causing havoc in their neighborhood. With Evinrude’s help, the rescuers are able to reach the ship on which Penny is held. Eavesdropping on Madame Medusa and Mr. Snoops, they learn that the Devil’s Eye is a diamond coveted by Medusa, and that Penny was captured so as to provide the criminals with one who could enter the underground pirate‘s cave wherein the gem is kept and recover it. Shortly after entering, Miss Bianca and Bernard attract the attention of Medusa’s half-tame crocodiles, Brutus and Nero. The crocodiles, who serve Medusa as guards to prevent or spoil Penny’s escape, attempt to devour the mice. In the resulting chase/battle, the ship’s pipe organ, some curtains, and Medusa’s patience are all broken. Medusa, who cannot tolerate mice, complicates the pandemonium by her panic, her summons of the incompetent Mr. Snoops, and her use of a large gun.

Bernard and Miss Bianca escape, later to visit a disconsolate Penny. Penny still maintains hope that she might have a family of her own; yet her resolve is waning. The arrival of two well-meaning mice, who speak of co-operation and faith (a concept made familiar to her by Rufus), raises her morale. Together, the three devise a plan, which is put into action on the following day.

Meanwhile, Ellie Mae has roused her neighbors to action. They wait only for Bernard’s message, which Evinrude is expected to deliver; once it has arrived, they will attack the steamship and rescue Penny. Evinrude, meanwhile, receives orders to find and bring Ellie Mae and her friends; en route to do this, he is pursued by hungry bats. He therefore takes refuge in an empty bottle, delaying delivery of his message.

During the next morning, Madame Medusa and Mr. Snoops send Penny into the cave to find the Devil’s Eye. With her are Miss Bianca and Bernard, concealed in a pocket. The cave itself is implied to have been a treasure-trove used by pirates to store their plunder, before the crew (presumably) fought among themselves and killed each other. After a brief search, the friends discover the Devil’s Eye inside the skull of one of the pirates; the means of its concealment therein is not explained. As they are opening the skull in order to bring the gem out, the oceanic tide rises and floods the cave. Miss Bianca, Penny, and Bernard just barely manage to retrieve the diamond and escape.

Medusa, passionate and jealous in greed, takes possession of the diamond immediately. Rather than give Snoops a 50% share in it as she had evidently promised, she takes it entirely for her own, concealing it in Penny’s teddy bear. When both Snoops and Penny protest, she threatens to kill them.

Evinrude, eluding the bats, arrives at Ellie Mae’s house. There, the tired insect is given a drop of Luke’s stimulating beverage, whereupon he gives the order to charge. The locals then run in a body to the riverboat.

As Medusa is backing away from Penny and Mr. Snoops, clutching the toy bear in which is the diamond, Bernard trips her up by means of a cord. She loses control of the diamond. Before she can recover it, Ellie Mae and her friends attack, punishing Medusa relentlessly for disturbing their peace. Medusa retaliates with gunfire, causing the rebels to flee; they are met by Brutus and Nero. Just as the crocodiles are poised to kill the smaller animals, Bernard and Miss Bianca trick them into entering a cage-like elevator, which is then closed upon them.

The locals, following Penny’s plan, set off flares and fireworks (formerly used by Mr. Snoops on Madame Medusa’s orders) into the riverboat’s living quarters, while Penny and the mice commandeer Medusa’s “swampmobile” (a type of motor-boat used by Medusa to traverse the bayou). Medusa attempts pursuit, but is thwarted. By the flares and firecrackers, the ship is caused to explode and sink. Medusa is left clinging to one of its smokestacks while the crocodiles (whom she had abused in her desperation) attack her from below. Mr. Snoops, rowing on a makeshift raft, laughs at the sight of her ruin.

The Devil’s Eye is given to the Smithsonian Institution, and Penny is adopted by a new father and mother. Bernard and Miss Bianca remain partners in the Rescue Aid Society’s missions and soon after depart on Orville, accompanied by Evinrude, to a new rescue mission.