Splash
As a boy, Allen Bauer, who does not know how to swim, leaps into the water off Cape Cod after something only he can see. He is rescued from drowning by a young mermaid, and an instant connection forms between the two. When his parents retrieve him, no one sees the mermaid, who weeps at the loss of her new friend before departing. Allen comes to believe the encounter was a near-death hallucination, but his bond with the mermaid proves so strong that his subsequent relationships with women invariably fail as he subconsciously seeks the connection he felt with the mermaid.
Years later, now co-owner with his womanizing brother Freddie of a wholesale fruit and vegetable business in New York City, Allen, depressed after his latest breakup, returns to Cape Cod, where he briefly encounters eccentric scientist Dr. Walter Kornbluth, and again falls into the sea. He wakes up on a beach where he encounters a beautiful nude woman who, unknown to him, is the mermaid he met as a boy (she is wearing the same necklace she wore as a girl). He instantly becomes attracted to her, as she again saves him from drowning. But after kissing him, she dives into the sea and leaves Allen to return home. Kornbluth, while diving seeking proof of strange sea creatures, also encounters the mermaid in her sea form, whom he becomes obsessed with finding again.
The mermaid finds Allen's wallet that he dropped in the water and decides to find him in New York. (In one scene that was deleted, the mermaid meets with a sea hag who tells her that she can only stay six days from the sea, but she has to wet her tail every day, which explains the bathtub scene later in the movie. The movie instead clarifies that mermaids become human after they have been dry long enough but return to mermaid form if their bodies are soaked with water.) She comes ashore at Liberty Island nude, where she is arrested for indecent exposure. The crowd boos at the cops for arresting a beautiful woman just because she is nude. Garnering information from Allen's wallet (which she still carries), the cops call Bauer, who races to the police station. She gets released in Allen's care. After a series of comedic events where the two are unable to control their urges, the mermaid goes out to buy some clothes at Bloomingdales. She later picks up English from watching television all day at Bloomingdale's. Needing a name, Allen lists some choices as they walk. While doing so when on Madison Avenue, he asks himself aloud "Where are we? Madison," which the mermaid picks as her name.
Allen quickly falls in love with Madison, not realizing she is the mermaid he has subconsciously sought a reunion with all his adult life. While Madison requites his love, Allen finds it hard to understand her unusual behavior (for example, eating an entire lobster, shell and all, at a White House dinner) and has trouble accepting that this relationship might go well. Meanwhile, Kornbluth, realizing that the nude woman at Liberty Island was the mermaid he had encountered, pursues the couple, although neither realize it at first.
When Kornbluth finally proves Madison is a mermaid by dumping water on her and turning her legs into a tail, she is taken in by government scientists for examination. At first jubilant at having proven his belief that mermaids exist, Kornbluth, who had only wanted people to stop thinking he was insane, deeply regrets his actions when Madison is studied like a laboratory specimen and slated for dissection. Meanwhile, Allen, stunned by the revelation, lapses into mortification at having fallen in love with a "fish". "People fall in love every day," he bemoans, "and look what I got." But Freddie finally sets aside the lascivious humor that has typified him throughout the movie to break through Allen's self-absorption: "People fall in love every day, is that what you said? Yeah? Well, that's a crock. It doesn't work that way." Freddie angrily berates Allen for giving up on Madison, with whom he has seen his brother so happy over the past few days. "A lot of people will never be that happy!" Freddie declares. "I'll never be that happy!" Realizing Madison's situation is more important than his mixed emotions, Allen calls various government officials, but no one will arrange for her freedom or even tell him where she is being held.
Desperate, Allen confronts the guilt-ridden Kornbluth, who still has clearance to the lab where Madison is imprisoned. Impersonating two Swedish scientists, the brothers enter the lab with Kornbluth, then Allen and Kornbluth emerge with a figure concealed in blankets, claiming it to be the scientist impersonated by Freddie, who was attacked by "the creature," who is now too dangerous to approach; the panicking security guard closes off the lab until the head scientist arrives to receive a cheerful greeting from Freddie, who had remained in the lab while Allen and Kornbluth smuggled Madison outside in the blankets. After a pursuit through the streets of the city, she jumps back into the ocean. When she reveals that Allen can survive under water as long as he is with her, Allen realizes she was the young mermaid he had met so long before, and although Madison warns him that if he comes to live in the sea, he will be unable to return to the surface world (she does not specify why), they both continue their lives in what appears to be an underwater kingdom.
