Serial Experiments Lain is an anime series about an adolescent girl in suburban Japan named Lain Iwakura, and her introduction to the Wired, an international computer network. The original idea of the series was produced by production 2nd, the story was written by Chiaki J. Konaka, the original character design was done by Yoshitoshi ABe and it was directed by Ryutaro Nakamura. Lain is produced in English in North America by Geneon and in Singapore by Odex.

Serial Experiments Lain raises questions about God, the collective unconscious, the Internet, conspiracy theories and many other themes common in cyberpunk literature. Fans of the series generally cite it as a good example of anime as literature which invites and rewards close critical analysis.

Serial Experiments Lain was also a PSX game in Japan. The story for the game came first and then they started work on the anime useing some of the plot and the main character Lain. Even though they were produced at the same time the anime was showed first in Japan in 1998. The storylines were different and did not have the same characters.

The series begins with the suicide of Chisa Yomoda. After being told by her classmates of an posthumous e-mail from Chisa that they believe is either a hoax or a prank Chisa set up. However, the main character, Lain Iwakura (岩倉玲音 Iwakura Rein) is unconvinced and decides to check it out. She logs on to her personal computer (or "NAVI", named after Knowledge Navigator concept) and discovers an e-mail from Chisa explaining that she has abandoned her flesh and is still alive in the Wired (a large computer network with striking similarities to the Internet). Lain begins to tentatively explore the Wired. She believes that the Psyche chip will allow her to enter the Wired and the series follows her gradual evolution into, or realization as, an omnipresent and omnipotent being who has grown independent of the Wired.

Along in her quest for answers, Lain becomes a famous character throughout the Wired and she gradually loses interest in things of the "real" world, and more into the "Wired" world. She discovers powers and unimaginable abilities within the Wired, even able to walk through it, and finally comes across a big question: "Who is Lain?" While trying to figure herself and the world out, the Real world and the Wired world are merging.

Truth was, when a Tachibana Industries CEO, Musame Eiri, developed Protocol 7 (based up the Eight Circuit Model of Consciousness, in which, the seventh circuit is the neurogenetic circuit), which allowed the "collective consciousness" (concept developed by Jung) to rise to a conscious level by using the Schumann resonance (the electromagnetic waves at 7.83 HZ that travel through the Schumann Cavity; the air between surface and ionosphere), he found the means to become "a God" as he quotes. By transferring his consciousness to the Wired and destroying his corporeal body (as indicated in Chisa Yomoda's e-mail) he managed to pass to the Eigth Circuit (neuro-atomic circuit, within which the helix of DNA allows the consciousness to transcend to the future version of oneself) and achieve immortality, or rather, continious existence. By means to achieving his status as a God, Eiri created Lain as a part of Protocol 7 and/or stumbled upon Lain as a result of Protocol 7 (never properly explained which); and he has his worshippers, The Knights of the Eastern Calculus. By giving Lain a new identity as a teenage girl, and thus, a new awareness, Eiri launched the "serial experiments" conducted by Tachibana labs. The constant (supposed) hallucinations Lain suffers from throughout the series is the old awareness she had inherited resurfacing, and/or, her own vision of the Eight Circuit. As stated appropriately in the series, by this argument, "Lain is God"; collectively aware, able to do anything. However, Lain's encounter with Eiri went off as a bitter one - as Lain had slaughtered all the Knights members, and thus, destroyed Eiri's worshippers, denouncing his position as God. Eiri counters this by the argument of Lain being his only worshipper, and ergo, the guarantee of his status. By the end of the Series, in her encounter with Alice (Arisu in the Japanese version), when Eiri interrupts, Lain states that the idea of using Schumann Resonance as a means to initiate Protocol 7 could not have been Eiri's idea alone, and that Eiri was simply an "acting" God; therefore, not truly a God, just a being that proclaimed itself one. Eiri's final act of madness which overloads his presence and makes it collapse upon itself (during which he manages to gain an inconsistent corporeal shape, perhaps by the means of regulating the electrons to draw protons and neutrons to form flesh). This causes Alice to slip into a traumatic shock, after which, Lain decides to erase the memories of all that has happened (with her) from everyone's minds to avoid it and restore everything. She states, "If it isn't remembered, it never happened.". A curious point occurs afterwards; Eiri is shown to be alive. While that is in accordance with the overall plot, it is an occurance that hasn't been explained properly. However, a theory in the series' own script shows that the Roswell Aliens were a result of the collective unconscious generating the image of the future (The human evolution), which is also in accordance with Eiri's appereance; the generation of collective unconscious as a vision of the "past", which is triggered by Lain.

Another aspect of the series is the constant identity crisis Lain enters upon encountering her "Wired" self; every-so-often asking the questions "Who am I?", "Who are you?", "Why are these happening?" and stating "I am me!", "There is only one me!", "You are not me", she inquires to whether her being is what she thought it was, a normal girl, or something else. In the end, she accepts her position as the only thing close to God that ever came into existence.