Fact1: England is playing against Germany in World Cup final, Fact2: Roddy schemes to get rid of Sid by luring him into jacuzzi, Fact3: archenemy sends rat henchmen for stealing back father 's prized ruby, Fact4: ruby breaks it in front of Rita, Fact5: Rita takes him to Kensington
Output: Roddy St. James is an upper class pet rat who makes his home in a posh Kensington flat. While his owners are away on holiday, Roddy plays around the house. A common sewer rat named Sid comes spewing out of the sink and decides to stay, especially as England is playing against Germany in the World Cup final. Roddy schemes to get rid of Sid by luring him into the jacuzzi, which is actually the toilet. Sid is not fooled and instead throws Roddy in and flushes him away into the sewer. Roddy discovers a city resembling London, Ratropolis, made out of various bits of junk, and meets Rita Malone, an enterprising scavenger rat who works the drains in her faithful boat, the Jammy Dodger. Rita is irritated by Roddy initially, but ends up taking him along, while her archenemy The Toad sends his rat henchmen, Spike and Whitey, after her for stealing back her fathers prized ruby. The Toad loathes all rodents to the point of hateful obsession, and plans to have Roddy and Rita frozen with liquid nitrogen inside an icemaker. The pair escape, and Rita takes a unique electrical cable that, unknown to everyone but the Toad, is required to control the floodgates. Roddy finds that the ruby is a fake and breaks it in front of Rita, enraging her, for she cannot now get the money she needs for her large family. Roddy offers her a real ruby if she takes him back to Kensington. Agreeing to the deal, the pair first stop to visit her family before setting off. During Roddys stay, he overhears a conversation that causes him to think that Rita has doublecrossed him, so he steals the Jammy Dodger. When Rita catches up to him, she is able to clear up the misunderstanding. The pair evade a pursuit from Spike, Whitey, and their accomplices. Incensed at his minions’ repeated failures, The Toad sends for his French cousin, an infamous mercenary known as Le Frog Jean Reno. It is revealed that The Toad was once Prince Charles pet, but was replaced by a pet rat and flushed down a toilet, resulting in his hatred of rodents. Le Frog and his subordinates intercept Roddy and Rita and retrieve the cable, but the duo use a plastic bag to lift themselves out of the sewer, snatching away the cable during the ascent and get Roddy home, though the Jammy Dodger is destroyed. Back home, Roddy pays Rita the promised ruby and an emerald, then shows her around his house. She at first believes he has family in the home, but noticing his cage, she realizes he is a pet. Rita tries to persuade Roddy to come with her, but he is too proud to admit that he is lonely. She departs, but is soon captured by The Toad. Talking to Sid about halftime, Roddy pieces together The Toads plan: to open the gates during halftime of the World Cup, when all the humans will most likely be using their toilets, causing a great flood and drowning the rats and their underground city in sewage. The Toad could then use the depopulated city as a home for his own tadpole offspring. Roddy gives Sid his cushy position and has Sid flush him back to the sewers to find Rita and save the city. Together, they defeat The Toad and his henchmen and freeze the wave of sewage with his liquid nitrogen. Rita and Roddy build the Jammy Dodger Mark Two and set off in her with Ritas entire brood. A newspaper article reveals England had lost on penalties. In a postcredits scene, Roddys former owner Tabitha returns home with a new pet cat, which scares Sid.