In the late 21st century, global warming has flooded the coastlines, wiping out coastal cities (i.e. Paris, Amsterdam, New York City, Venice, etc.) and drastically reducing the human population. There is a new class of robots called Mecha, advanced humanoids capable of emulating thoughts and emotions. David (Haley Joel Osment), a prototype model created by Cybertronics of New Jersey, is designed to resemble a human child and to display love for its human owners. They test their creation with one of their employees, Henry Swinton (Sam Robards), and his wife Monica (Frances O’Connor). The Swintons’ son, Martin (Jake Thomas), was placed in suspended animation until a cure can be found for his rare disease which is caused by the Sinclair virus. Initially frightened of David, Monica eventually warms up enough to him to activate his imprinting protocol, which irreversibly causes David to have an enduring childlike love for her. He is also befriended by Teddy (Jack Angel), a robotic teddy bear, who takes it upon himself to care for David’s well-being. A cure is found for Martin and he is brought home; as he recovers, it becomes clear he does not want a sibling and soon makes moves to cause issues for David. First, he attempts to make Teddy choose whom he likes more. He then makes David promise to do something and in return Martin will tell Monica that he loves his new “brother”, making her love him more. The promise David makes is to go to Monica in the middle of the night and cut off a lock of her hair, which of course upsets the parents (not just through the act itself, but David isn’t supposed to go into their room at night). At a pool party, one of Martin’s friends unintentionally fully activates David’s self-protection programming by poking him with a knife. David grabs Martin, possibly for protection, and they both fall into the pool, where the heavy David sinks to the bottom while still clinging to Martin. Martin is saved from drowning, but Henry mistakes David’s fear during the pool incident as hate for Martin. Henry persuades Monica to return David to Cybertronics, where he will be destroyed. However, Monica cannot bring herself to do this and, instead, tearfully abandons David in the forest (with Teddy) to hide as an unregistered Mecha. David is captured for an anti-Mecha “Flesh Fair”, an event where obsolete and unlicensed Mecha are destroyed in front of cheering crowds. David is nearly killed, but the crowd is swayed by his fear (since Mecha do not plea for their lives) into believing he is real and he escapes with Gigolo Joe (Jude Law), a male prostitute Mecha on the run after being framed for murder. The two set out to find the Blue Fairy, who David remembers from the story The Adventures of Pinocchio. He is convinced that the Blue Fairy will transform him into a human boy, allowing Monica to love him and take him home. Joe and David make their way to Rouge City, a Las Vegas-esque future city located along the Delaware River. Information from a holographic answer engine called “Dr. Know” (Robin Williams) eventually leads them to the top of Rockefeller Center in the flooded ruins of Manhattan. There, David meets an identical copy of himself and, believing he is not special, becomes filled with anger and destroys the copy Mecha. David then meets his human creator, Professor Allen Hobby (William Hurt), who excitedly tells David that finding him was a test, which has demonstrated the reality of his love and desire. However, David learns that he is the namesake and image of Professor Hobby’s deceased son and that many copies of David, along with female versions, are already being manufactured. Sadly realizing that he is not unique, a disheartened David attempts to commit suicide by falling from a ledge into the ocean, but Joe rescues him with their stolen amphibicopter. David tells Joe he saw the Blue Fairy underwater and wants to go down to her. At that moment, Joe is captured by the authorities with the use of an electromagnet, but he sets the amphibicopter on submerge. David and Teddy take it to the fairy, which turns out to be a statue from a submerged attraction at Coney Island. Teddy and David become trapped when the Wonder Wheel falls on their vehicle. Believing the Blue Fairy to be real, David asks to be turned into a real boy, repeating his wish without an end, until the ocean freezes in another ice age and his internal power source drains away. Two thousand years later, humans are extinct and Manhattan is buried under several hundred feet of glacial ice. The now highly advanced Mecha have evolved into an intelligent, silicon-based form. On their project to study humans — believing it was the key to understanding the meaning of existence — they find David and Teddy and discover they are original Mecha who knew living humans, making the pair very special and unique. David is revived and walks to the frozen Blue Fairy statue, which cracks and collapses as he touches it. Having downloaded and comprehended his memories, the advanced Mecha use these to reconstruct the Swinton home and explain to David via an interactive image of the Blue Fairy (Meryl Streep) that it is impossible to make him human. However, at David’s insistence, they recreate Monica from DNA in the lock of her hair, which Teddy had saved. One of the Mecha warns David that the clone can live for only a single day and that the process cannot be repeated. The next morning, David is reunited with Monica and spends the happiest day of his life with her and Teddy. Monica tells David that she loves him and has always loved him as she drifts to sleep for the last time. David lies down next to her, closes his eyes and goes “to that place where dreams are born.” Teddy climbs onto the bed and watches as David and Monica rest peacefully together.
故事設定於近現代的未來世界，世界因地球暖化而導致沿海多數地區被海水淹沒，而為了抑制人口成長，懷孕及產子也必須經過嚴格的審查制度，為了取代多數人口的生產力，機器人的發展技術也因此活躍了起來。有一天，製作機器人的科技公司運用了新技術，製造了世界第一個會愛人的機器男孩大衛，送給了同公司員工亨利，因為兒子生病而不在身邊，所以亨利將他帶回家陪伴自己的妻子莫妮卡，用來代替其因為絕症而進行冷凍睡眠的兒子一同生活。而因為大衛的外表與個性幾乎與平凡男孩無異，而讓原先很排斥大衛的莫妮卡開始接受了他，甚至把當作自己的親生兒子。 起先大衛以為莫妮卡會永遠的愛他，但某一天兩夫妻的真正的兒子馬丁因為絕症奇蹟似的康復而從冷凍睡眠中甦醒並出院。而莫妮卡接注意力轉移馬丁身上， 導致了大衛的失寵。大衛在某次馬丁的生日派對無意間差點害他淹死在泳池中，而為了防止此事再次發生，亨利向莫妮卡提議將大衛送回機器人公司銷毀，但莫妮卡 對大衛仍有感情，認為此事太殘忍而反對，但為了自己的兒子的性命著想，只好忍痛私自將大衛帶到森林中拋棄。 為了回到自己認定的母親莫妮卡身邊，大衛與一起被扔掉的機器玩具熊泰迪一起踏上了旅程，旅途中結識了逃亡中的牛郎機器人喬。之前也從莫妮卡講的故事中得知了木偶奇遇記中 藍仙女的傳說，大衛認為藍仙女就她實現願望-變成真正的小男孩，所以大衛改踏上了尋找藍仙女的旅程。之後大衛隨喬到達了製作大衛的公司，大衛看到很多與自 己完全一樣的“大衛”機器人，他無法忍受，因為他認為莫妮卡只屬於他一個人，於是跳海自殺。於後被喬救起，但喬之後被警察抓走。大衛一個人乘潛水艇在海中發現了被海水淹沒的一座樂園，裡頭矗立著一尊藍仙女的雕像，大衛認為自己找到了，便拼命的向其請求自己想變成真正的小男孩的願望。 大衛在潛水艇中一直請求藍仙女，直到大衛身體的能源用完，海水也被冰凍起來。時間經過了2000年，地球被厚實的冰層覆蓋，人類已經滅亡，只剩下機器人生存下來。一群意圖尋求根源的考古學家發現了在海中機能停止的直升機以及大衛，並再次將其啟動。 機器人告訴大衛地球的現況，也告訴他莫妮卡已不在人世，而為了表示對大衛的歡迎，機械人決定替大衛實現一個願望，就是利用機器人的克隆技術複製一個 一模一樣的莫妮卡，但因技術的限制，複製人只能存活一天，一旦再次睡眠後便會死去，而大衛也與莫妮卡的複製人度過了一生中最開心的一天，大衛終於實現自己 的願望，兩母子最後在夜幕一同沉沉的睡去。