Star Trek: The Next Generation’s Data remains one of the most iconic androids in fictional history. His confusion and appreciation for human behavior provided a much-needed outside perspective to the day-to-day social systems on the Enterprise. Data remains a part of the franchise in modern incarnations, appearing regularly inStar Trek: Picard. Though Data is the face of the family, he’s the youngest of his creator’s artificial children. His prototype older brother B-4 is less iconic.
The most prominent science fiction universestend to expandbeyond their starting medium.Star Trekwas a TV show that spawned a dozen other series, movies, video games, and enough novels to fill hundreds of thousands of hours. Those books often add extraneous, non-canonical details to the minor figures who disappear into the space between episodes. Many dive into the expanded universe to see how their favorite lesser characters live.

What happened to B-4 onStar Trek?
B-4 first appeared in the 2002 tie-infilmStar Trek: Nemesis. The Enterprise crew finds B-4 dissembled on the planet Kolarus III. B-4 resembled Data physically, but his mental capacity was significantly weaker. He couldn’t remember how he arrived on Kolarus III or why he was in pieces. Data saw his struggles reflected in his long-lost brother. To help B-4, Data copied his memories and experiences onto his brain. B-4 found that he couldn’t remember many details he should have learned from Data. The Enterprise crew discovered rogue programs buried in B-4’s software, forcing him to download vital information about Federation starships and their encrypted messages. Shinzon, the film’s villain, planted B-4 as a trap and unwilling spy.Geordi La Forge deactivatedB-4’s spyware while Data took his place on Shinzon’s ship. Data saved Picard from Shinzon’s ship but died in the conflict. B-4 demonstrated some of Data’s memories when he idly sang Irving Berlin’s “Blue Skies,” which Data had recently performed at Will Riker and Deanna Troi’s wedding.
Whatever potential B-4 showed as Data’s replacement was not explored. He didn’t appear again untilStar Trek:Picardseventeen years later. B-4’s dissembled body sat in a drawer for untold years at the Daystrom Institute. The Institute, named for brilliant computer scientist Doctor Richard Daystrom, studied B-4’s advanced synthetic technology. Picard visited his long-unconscious parts, hearing from a doctor that B-4 still lacks most of Data’s memories. The company moved B-4’s head to Daystrom Station, a black site research facility hidden from most. Altan Soong, the son of Data’s inventor, Noonien Soong, borrowed B-4 for a new project. He set out to create an android with parts of every Soong-type consciousness. Altan died before he could finish this amalgam. Its conflicting minds fought for control of its body.Data took over, possessing the most refined brain. Though B-4 was subsumed beneath his younger brother’s intelligence, he remains part of the new Data.

Who is B-4 onStar Trek?
B-4 is one of three failed prototypes created before Noonien Soong accomplished his goalswith Lore and Data. B-4’s positronic brain was far less complex or efficient than his younger siblings. He could barely understand simple concepts, while Data remained extremely intelligent. B-4 took Data’s memories, but his intellect never became impressive. Though he could be as emotionally engaging as Data, B-4 spends the overwhelming majority of his screen time dissembled and potentially held in a storage closet. As part of Data’s new combined form, B-4 will continue to be part of the series, though his personality is mostly Data’s memories. Data illuminated the difference in a conversation with Picard, where he says this:
I aspire, sir, to be better than I am. B-4 does not. Nor does Shinzon.

Does B-4 appear in otherStar Trekmedia?
B-4 appears in several novels and comics. He usually remains a part of Data, as he is in the modern show. The 2012Cold Equationstrilogysees Doctor Soong, freed from death by a convincing android body, use B-4’s copy of Data’s memories to rebuild him. The 2009 comic seriesStar Trek:Countdownis connected to the J. J. Abrams reboot and the MMO. That series depicted Geordi La Forge installing Data’s emotion chip in B-4, which allowed Data to overtake B-4’s consciousness and return from the grave in his body. As usual, B-4 is a rather on-the-nose external hard drive for Data.
B-4 is a tragic figure in theStar Trekcanon. He’s a failed experiment, abandoned when his brain failed to live up to his father’s expectations. A monster uses him to hurt the innocent, but he enjoys hisfirst taste of intellect. B-4 is abandoned in favor of his more intelligent siblings. That experience extends to being overwritten by superior mental power. He deserves better, but fans love Data, and a lesser iteration of the classic android can’t live up. It may be cruel, but Data isn’t known for his empathy.