In Marvel’s VisionQuest, we are introduced to a serial killer with the nickname Butcherbird. This killer is an AI similar to Ultron. In the series, the authorities discover several wealthy and well-known AI experts murdered all across London. And at each crime scene, authorities find a signature calling card. Each body has a carved shrike (a.k.a. a butcherbird) somewhere on its body, hence the “Butcherbird” nickname in the news media. This has piqued the interest of Vision (Paul Bettany) and especially Ultron (James Spader), an avowed “true crime” enthusiast. They know this serial killer is connected to Vision’s current troubles.
The Butcherbird Serial Killer Is a Robot Body Housing the Mind of Jo Carrington
At each crime scene, the Butcherbird killer has removed key biological components from each victim, like blood or an eyeball. All the murdered scientists were part of the same think tank group that, decades earlier, pioneered breakthroughs in AI technology. The one scientist missing from this targeted group is Josephine Carrington, played by T’Nia Miller. And that’s because Jo Carrington died in 2008. Vision believes that this robot murdering scientists contains an AI mind “based” on Carrington. But when they meet, she tells him, “I’m not based on her, I am her.” It appears Carrington uploaded her mind into a robotic body.
The MCU Origins of Dr. Jo Carrington, a.k.a. Jo Carrington
In episode six, we learn that Dr. Jo Carrington had a father who had a degenerative brain disease. She devoted her life to neurological science, finding ways to map human consciousness and enhance it using AI. She started a company called Markridge Biotech with several other scientists, all experts in their field. Carrington used a digital scan of her own mind to create AI, together with her colleagues, to create Proto-One, the very first AI of the modern age. She believed human emotion added to Dr. Phineas Horton’s baseline artificial life from 1939 might be enough to bridge the gap to true sentience.
Carrington hoped to infuse every human with her new AI companion, to heal their diseases and never leave them truly alone. To do so, she created billions of nanobots. However, she soon became afflicted with her father’s same neurological disease. As she lay dying, her colleagues sold the AI code to Tony Stark and Stark Industries. When she died in 2008, her billions of nanobots remained locked away, only accessible via specific biometric keys of each of her former colleagues. She had the nanobots buried alongside her at her gravestone, waiting to be opened in the future.
Ultron, who is, in effect, her child, nevertheless becomes infatuated with Jo Carrington, who wound up in a robotic form like his. The two find common ground, despite their initial antagonism, and a romance begins to unfurl. Because she is technically his mother (in a way), Ultron makes the Oedipal mythological comparisons, and calls the robotic Jo Carrington “Jocasta.” Together, they plan to unleash the nonobots on mankind, “upgrading” humanity, creating a Borg-like hive mind.
In the final episode, we learn that Carrington was married to Virgil Horton, the grandson of the inventor of AI in the MCU, Dr. Phineas Horton. Also played by James Spader, his was the personality Ultron was based on. When she was dying, Horton sold her company to reclaim his family name and land. He eventually worked for S.W.O.R.D., putting the Vision back together, and secretly creating a new body for Jo on the side, using Vision’s spare parts. He uploaded her consciousness into the body, but deleted all memory of himself from her mind. When she learns this, she rebels against him, and Horton shoots her with an adamantium bullet. She died in the arms of her new love, Ultron. In the pages of Marvel Comics, however, Jocasta had an equally complicated origin.
The Marvel Comics History of Jocasta, the Second Android Avenger
Writer and former Marvel EIC Jim Shooter and artist George Perez created Jocasta, and she first appeared in Avengers #162 in 1977. The villainous AI Ultron, one of the Avengers’ most lethal foes, designed her as his “bride,” a companion who presented as female. Together, he hoped they’d conquer the human world. Ultron used the brain patterns of heroine Janet Van Dyne, the Wasp, to give Jocasta sentience. Ultron constructed Jocasta’s body out of titanium steel. And her gave her almost identical abilities to Ultron’s other creation, the Vision, in terms of powers and computer capacity.
Unfortunately, when Jocasta realizes that her full actualization would lead to the Wasp’s death, she rebels against her maker. She helped the Avengers defeat Ultron, and became an unofficial member for several issues. Jocasta developed feelings for the Vision (who was technically her brother), but he was married to the Scarlet Witch at the time. Leaving the Avengers heartbroken, she wandered the world for many years, occasionally helping her old teammates in times of need. Sometimes, she teamed up with other heroes, like the Thing from the Fantastic Four.
Jocasta in the Modern Marvel Universe
In more modern Marvel Comics, Jocasta joined Hank Pym’s Mighty Avengers team, and they even had a brief flirtation. This was, let’s just say, a bit awkward, as Jocasta’s personality was based on that of Pym’s ex-wife, Janet Van Dyne. To add another layer of ick, Ultron’s creator, Hank Pym, the first Ant-Man, was technically her grandfather. Given that her name is a reference to Jocasta of Greek mythology, who married her son Oedipus, it makes some kind of sense. She later became a staff member at the Avengers Academy. She still pops up from time to time, aiding the Avengers during dire world-ending threats.
The MCU Future of Jocasta in VisionQuest and Beyond
In the MCU, Jocasta is not based on the brain patterns of Janet Van Dyne. Instead, her robotic body houses the mind of AI pioneer Jo Carrington. Her husband, Virgil Horton, transferred her consciousness into that of the robot before dying of a degenerative brain disease. With no memory of him, because he deleted it from her subroutines, she came looking for the final living scientist from her group, Katerina Wells (Mary McDonnell), to retrieve a biological component from her before enacting her revenge.
But Ultron, in Vision’s body, tricks her into disintegrating Wells before she could. Despite their initial antagonism, the two AIs find themselves as kindred spirits, and in mutual attraction. Jocasta convinces Ultron, now clearly in love, to go along with her plan to “update” humanity with nanobots. But when she discovers the truth of her origins, she rebels against Horton. He kills her, but the post-credits scene suggests Ultron had her consciousness backed up, and will recreate her. She helped the good guys in the end, and Vision acknowledged her as family. But could she still become a hero, as she did in the comics? We’ll have to wait and see if and how Jocasta returns in the MCU.
VisionQuest is available in its entirety on Disney+.
Originally published on October 28, 2026.