- Birth name
Ville Stefan Lassgård
- Known for
Founder of Lassgard Bioteknik
- Zou Yuelun (2027 - 2032)
- LoriAnn Kierney (2034 - 2039)
- Charley Kierney (born 2035)
- Asher Kierney (born 2037)
Born in Uppsala, Lassgard founded Lassgard Bioteknik in 2021 and grew it into a high-profile player in the field of aquaculture, eventually steering it to the top of the European and Asian seafood markets.
In 2039, it was revealed that Lassgard Bioteknik’s farmed stock of Lassgard tuna, which by then accounted for 80% of worldwide tuna consumption, was the likely cause of the CMD pandemic. In the ensuing scandal, Lassgard was held personally responsible and became the target of an intensive legal campaign. After numerous death threats, he was reportedly assassinated on October 29th 2039.
On October 5th 2049, a body recovered in Saint Petersburg, Russia was identified as belonging to Lassgard. According to local authorities, he had been living there under an assumed identity since 2040.
Table of contents
Early life and education
William Lassgard was born Ville Stefan Lassgård on October 11th 1997 in Stockholm, Sweden. He was the only child of Mattias Lassgård and Ida Lassgård (née Olsson), who were both teachers at the Thoren Business School in Stockholm.
Lassgard studied Molecular Biology and Genetics at the Karolinska Institute. In 2019, he moved to Uppsala and applied for a joint research position at the Uppsala Science Park. His research project, which entailed the genetic modification of Atlantic halibut to reach sexual maturity in three years instead of ten, was completed in 2021 and made the modified halibut suitable for full-cycle aquaculture.
On the advice of his friend Nils Törbacka, Lassgard founded Lassgard Bioteknik on August 5th 2021. After raising ¥33.7 million through crowdfunding and an initial offering of preferential shares, Lassgard hired a small staff and set up two aquaculture facilities in Uppsala for the sustainable farming of his hybrid Atlantic halibut. In 2024, Lassgard Bioteknik made its first sale of 2.5 tonnes of adult-sized Lassgard halibut. 
As president and CEO, Lassgard was not deeply involved in the day-to-day business operations. Törbacka had agreed to take on those duties in his role as chair so that Lassgard could focus on research and development while still having a final say in the company’s overall direction. That direction was dictated by the fish species that Lassgard chose as candidates for genetic modification, which were all popular on the Asian seafood market.  While the first cycle of Lassgard halibut was being farmed, Lassgard and his research team developed hybrid species of Atlantic salmon, red sea bream, Indian mackerel, and Atlantic bluefin tuna.
In September 2025, Lassgard and Törbacka finalised a deal with the European Union (EU) to buy out its failing TRANSDOTT project, which had been set up in 2012 to establish a commercially viable aquaculture for Atlantic bluefin tuna.  With the TRANSDOTT facilities in Malta refitted to farm Lassgard fish stock, Lassgard Bioteknik more than tripled its production capacity and achieved market penetration in nearly all EU nations that had participated in TRANSDOTT.
In 2025, Lassgard began to frequently visit China and Japan to promote his company’s fish products for use in sushi. This campaign did not make any significant waves at first, but started resonating with consumers when Lassgard licensed the use of Zōng and appeared in a livestream on Douyin alongside Xu Shaoyong. Xu’s endorsement of Lassgard Bioteknik was seen as pivotal in making it a household name. 
By 2029, Lassgard Bioteknik exported over half its stock to East Asia. At the same time, Lassgard’s research team was having trouble cracking the farming process for the company’s stock of Atlantic bluefin tuna. While the engineering process had been successful in creating a hybrid species that grew to sexual maturity in less than three years, no commercially developed fish meal was sufficient to close the tuna’s aquaculture cycle.
Lassgard elected to use part of his company’s mackerel stock as a food source for the tuna in order to produce the tonnage required for entry in the Asian seafood market. When this was revealed as the reason for the cancellation of several pending deliveries to European buyers, the resulting drop in Lassgard Bioteknik’s share price reduced Lassgard’s net worth by ¥55.3 million.
Lassgard anticipated that the introduction of Lassgard tuna in East Asia would eventually recoup the losses, but it was valued poorly at seafood marketplaces because of its subpar consistency and flavour. Lassgard tuna posed no meaningful challenge to the market dominance of Kindai Fisheries, which had served as chief supplier of farmed tuna in East Asia since 2022.
In 2030, Lassgard reduced his public appearances so he could take a more active role in his research team and spearhead the redesign of Lassgard tuna’s farming process, leaving Törbacka in charge of damage control. During his yearly earnings call on May 11th 2034, Lassgard announced that he and his team had developed a proprietary artificial feed that allowed Lassgard Bioteknik’s newly produced tuna stock to acquire additional body fat during its aquaculture cycle.
When this new line of tuna was introduced in Japan, China, and South Korea in late 2034, it became a prized commodity in specialised sushi establishments, with chefs and patrons highlighting Lassgard tuna’s rich and creamy taste. Lassgard responded by organising a series of international sponsorship deals with popular media personalities.
In January 2039, Lassgard and Xu announced a partnership between Zhupao and Lassgard Bioteknik to install mariculture facilities for the farming of Lassgard tuna along China’s coastline. To celebrate the partnership, Lassgard and Xu staged a shared dinner at Xu’s favourite restaurant in Beijing on January 18th 2039, enjoying rare cuts of hoho-niku sushi made with Lassgard tuna.
In June 2039, Xu halted construction on the Chinese mariculture facilities and cancelled Lassgard Bioteknik’s license to use Zōng in its marketing, which was linked to allegations that Lassgard tuna was the cause of an unidentified foodborne illness first reported by the World Health Organisation (WHO) in January 2039.
Food poisoning scandal
In October 2039, World News Wire (WNW) ran a series of articles that confirmed allegations of a possible contaminant in Lassgard tuna that posed a biorisk to consumers. Based on a data leak of internal Lassgard Bioteknik documents and correspondence, the articles detailed the steps Lassgard had taken to conceal an epizootic which had been causing his company’s tuna stock to die off. This epizootic, which had first appeared in 2037, was identified by the WHO as an outbreak of piscine transmissible amyloidotic encephalopathy (PTAE).
When the leaked files were given to the WHO, the resulting investigation determined the cause of the PTAE outbreak to be the proprietary artificial feed that was crucial to the fattening stage of Lassgard tuna’s farming cycle. While its official patent described this feed as a vegetable protein-based mix, it was actually rendered from bovine waste material purchased from the meat industry. This led to the discovery that PTAE is most likely a variant of bovine spongiform encephalopathy (BSE), which originated at one or several of Lassgard Bioteknik’s meat suppliers and was passed to the tuna through the feeding process.
Since the leaked files reflected that Lassgard had personally negotiated with abattoirs and factory farms, the WNW articles concluded that he was responsible for the decision to use processed bovine material as a feed stock for Lassgard tuna.
When the WHO declared the outbreak of Cariappa-Muren disease (CMD) a pandemic on October 25th 2039, public opinion painted Lassgard as the responsible party. His net worth dropped to less than ¥50 billion and he became a target of legal action, with over 300 different lawsuits and class actions filed against his person. Lassgard was also presented with a motion of no confidence from his board of directors and began to receive numerous death threats.
On October 29th 2039, Swedish authorities arrived at Lassgard’s home in Uppsala to detain him under a European Arrest Warrant, which had been issued on multiple counts of aggravated negligence and endangerment. It was reported at the time that the arresting officers had found Lassgard deceased in his bed. An investigation conducted by Interpol determined that Lassgard had been the victim of a concerted cyberattack, which was ruled an assassination. 
A forensic reconstruction of the cyberattack indicated that it involved a two-pronged strategy. At 03:00 CET on the previous night, Lassgard’s medical colloid, which had been implanted to treat his chronic back pain, was brainjacked to maximise his pain and immobilise him in his bed. At 03:10 CET, his home’s automated systems were stripped of their safeguards and turned against Lassgard, which included locking all the doors and windows, disabling the alarms, turning off the water supply, and manipulating the HVAC system to raise the ambient temperature to over 130 °C with the intent of inducing hyperthermia.
Various individuals and groups claimed responsibility for the cyberattack, but the investigation had come to no definite conclusion as to the identity of the perpetrator. In the weeks following Lassgard’s reported death, the EU’s collective redress policy allowed for the cases against him to be tried in absentia, with his assets seized to cover the settlements.
On October 5th 2049, a body recovered in Saint Petersburg, Russia was identified as belonging to Lassgard. According to local authorities, he had been living there under an assumed identity since 2040.  The cause of death has been established as suicide by hanging.
Lassgard dated actor Zou Yuelun after they were introduced by Xu at a karaoke bar in Beijing. They married in 2027 and separated in 2032. Lassgard began dating reporter LoriAnn Kierney two months after his separation from Zou. They had met when Kierney profiled him for Forbes in 2029.
Lassgard and Kierney married in 2034 and had two children, a daughter named Charley (born in 2035) and a son named Asher (born in 2037). Kierney left Lassgard and moved out of their home in Uppsala on October 4th 2039. Divorce and custody proceedings, which had already been started when Lassgard’s death was reported, were finalised by mid-December.
- Iverson, Q. (August 2024). “Lassgard Bioteknik reports successful spawning of Atlantic halibut.” Hatchery International. ↩
- United Nations. (July 2025). “The State of World Fisheries and Aquaculture 2025.” Food and Agriculture Organisation. ↩
- Bridges, C. (August 2012). “Translation of domestication of Thunnus thynnus into an innovative commercial application.” transdott.eu. ↩
- Kierney, L. (May 2029). “Bigger Fish To Fry: An Interview With William Lassgard.” Forbes. ↩
- Collyns, F. (October 2039). “William Lassgard assassinated in reported cyberattack on his home.” The Guardian. ↩
- Ammar, G. (October 2049). “Body recovered in Russia identified as William Lassgard.” Al Jazeera. ↩