"The Fourth Child" is the seventeenth episode of Neon Genesis Evangelion.
Disaster strikes unexpectedly when NERV-02, NERV's second branch base in Nevada, mysteriously disappears in a flash, resulting in the loss of everything in a radius of eighty-nine kilometers and thousands of people. The incident coincided with an experiment to install an S² Engine, capable of giving an Evangelion an unlimited power supply, into Evangelion Unit-04, one of the two new Evangelions which have recently finished construction in the United States. Panicking after the accident involving Unit-04, the United States government demands that Evangelion Unit-03, built in NERV-01, NERV's first branch base in Massachusetts, be removed from its soil as quickly as possible. As Unit-03 is about to arrive in Tokyo-3, Toji Suzuhara becomes the new pilot for it.
The episode opens with the Human Instrumentality Committee interrogating Misato about the incident with the Twelfth Angel. The Committee seriously considers the possibility that the Angel was trying to communicate with mankind and took the Eva for that purpose, but Misato, acting as a proxy for a mentally disturbed Shinji, is incapable of conclusively answering what happened. Lorenz ends the meeting, and talks to Gendo.
Toji is seen in the hospital, and some of the hospital staff chat with themselves about how caring he is as a brother, and how nice he is to take care of his injured sister (hurt at the beginning of the series as one of the unnamed casualties of the battle with Sachiel). Gendo and Rei enter NERV Headquarters, and Gendo asks a few generic questions about Rei, such as how she is feeling and how she finds it at school. He does not make any further enquiries about her in a personal regard. Back at school, Toji embarrasses Shinji and Asuka by saying they fight like a married couple.
An orbital view of Post-Second Impact America is seen, with a small red dot spreading across the continent. Absolute panic ensues in the bridge, since NERV's Second Branch in Nevada has completely vanished. Misato, Ritsuko and the bridge trio review the incident, and notice that the disappearance took place at the same time that the restored S² Engine sample was to be installed on Evangelion Unit-04. A ridiculous 32,768 possibilities for the accident abound, including sabotage. Ritsuko suspects that the branch was swallowed into a Dirac Sea like Unit-01 had previously, and when Misato criticizes the idea of using things they don't fully understand, Ritsuko thinks to herself, "Just like the Evas." Later, on the escalator, Ritsuko informs Misato that the U.S. Government is sending over Evangelion Unit-03 to them from the United States, to prevent First Branch from being lost as well.
Ritsuko and Gendo discuss the usage of the dummy system, and Gendo orders the data to be installed on Unit-01 and Unit-02. Ritsuko says that the errors in the Dummy System make it risky to use for the first activation of Unit-03, but there is a candidate for whom a core can be readied immediately. Misato is surprised to discover who the Fourth Child is, and decides not to tell Shinji. Fuyutsuki and Gendo, on a train ride, discuss matters pertaining to Tokyo-3 and mankind, as well as the matter of Unit-04's catastrophic accident.
Toji has class duty- he and Shinji go over to Rei's place to deliver a bunch of printouts. The room is in an absolute mess, as always, and Shinji decides to clean up while he's at it. Rei soon returns, and surprised, thanks Shinji for cleaning up. She later realizes that she has never said "Thank you" to anybody, not even Gendo. During synch tests, Shinji's synch level is found to be dropping after the incident with Leliel.
Next day, Toji is called away at lunchtime to see the Principal. Inside, Ritsuko is heard greeting him, and he does not reappear until long after lunchtime, and seems oddly preoccupied. Kensuke talks with Shinji, telling him about Unit-03's arrival to Matsushiro and Unit-04's loss, and seems somewhat annoyed that Shinji, as an Eva pilot, does not know. Asuka, trying to get Kaji's attention, sees synch test data in Kaji's office, and when she sees who the Fourth Child is, whines loudly. Kaji later tries to flirt with Maya, much to Misato's disgust, and he tells her the truth about the Marduk Institute and the Eva pilots.
Shinji and Kaji go out, and discuss matters of life with each other. Kaji tells Shinji that once he gets to meet a person, he actually becomes very open indeed- a point that Shinji does not seem to realize himself. The Episode ends with Hikari cooking a meal for Toji and a strangely happy Toji shooting hoops.
- Episodes 16 and 17 form a figurative "irony bomb" when juxtaposed with Episodes 23 and 24. In episode 16, Ritsuko and Gendo stand beside Unit-01 as it is washed after its bloody "rebirth" from Leliel, and Gendo is oblivious to the dark look on Ritsuko's face when he invites Rei to eat with him. In Episode 23, Ritsuko thinks Gendo replaced her with Rei, and destroys the dummy system. Next episode, Unit-01 is washed after killing Kaworu, with Rei standing at Gendo's side exactly where Ritsuko did.
- The title of the Episode in English is "Fourth Children", in line with the Eva pilots being referred to as the "Nth children". In their U.S. release, ADV rendered this on the DVD cover as "Fourth CHILD" although "Fourth Children" remains unchanged in the Episode title.
- Old versions of the script had Toji speaking to his little sister (who is not seen and has no dialogue) telling her that she would be transferred to a new hospital the next day - the day of the Bardiel attack. 1
- Ritsuko and Gendo state in Episode 04 that there is no candidate they can use following Shinji's disappearance and prior to Asuka's arrival (Rei was still in bandages at that stage). There is no stated reason for the choice of Toji, once again leaving the question "Do they select the pilot or the soul first?" unanswered.