I knew the battle between Hewlett-Packard (H.P.) and Mike Lynch was a hate-filled conflict. But I had not realized how much writing a book about the life of the U.K.’s first dot-com billionaire would be like lancing pus-filled boils—or how much willful blindness was involved on all sides. As one British investor told me, “You’ll find it’s like lifting up a rock and finding all sorts of nasty things underneath.” He wasn’t wrong.

When I first started researching my book, in 2024, the famously irascible 59-year-old was still alive. At that point in my writing, Lynch had been accused of fraud in the 2011 sale of his corporate-software company, Autonomy, to H.P., and was on house arrest while awaiting a criminal trial in San Francisco, where he faced the possibility of two decades in jail.

Things moved quickly from there. Just a few months after his surprise acquittal by a U.S. jury, Lynch tragically drowned aboard his yacht off the coast of Porticello, Italy, during a freak storm, along with his 18-year-old daughter, Hannah; his long-standing New York attorney, Chris Morvillo; and four others. One day earlier, Stephen Chamberlain, Lynch’s co-defendant in the U.S. trial, had been hit by a car while out running and killed. It was the weekend of August 18, the same date that H.P. had bought Autonomy all those years before. The back-to-back tragedies formed a truth stranger than fiction.

“You’ll find it’s like lifting up a rock and finding all sorts of nasty things underneath.”

From the start, Lynch was someone who had defied the odds. Born to a working-class family in Essex, he smashed through Britain’s notoriously rigid class system to win a place at Cambridge and start a successful tech company during the dot-com boom.

He was sparklingly intelligent, creative, and charming, and his philosophy in business and in life was underpinned by Bayesian probability: the theory that the likelihood of something happening is informed by prior evidence. (“Bayesian” was also the name Lynch gave to his ill-fated yacht.)

Lynch sold Autonomy to H.P. for $11 billion. In less than a year, he was fired by Meg Whitman, the former C.E.O. of eBay and then C.E.O. of H.P., and accused by the company of tampering with Autonomy’s numbers to make it look more successful than it was.

Lynch always vehemently denied any wrongdoing. He accused H.P. of mismanaging the acquisition of Autonomy, of making it an “orphaned child” within the larger corporation. Yet in Britain, rumors had swirled around Autonomy for some time. Analysts in London had been sounding the alarm on its finances, and the company had a terrible reputation as a place to work, with Lynch being regarded as an ogre.

The wreckage of the Bayesian was salvaged in June of 2025, 10 months after it sank off the coast of Porticello, Sicily.

But it was only when I started contacting people who worked at Autonomy that the extent of its toxic culture was laid bare. One of Lynch’s offices had a tank of piranhas in which he threatened to dunk underperforming salespeople. Another had meeting rooms named after Bond villains. He would regularly scream at his employees when they displeased him.

Many of the former employees I was in touch with expressed fear of what speaking out would mean—even after Lynch was dead. There was one group of women who would talk to me only on the condition that they could be interviewed together, because they needed the support from one another. A group of men referred to themselves as the “battered wives.” Others told a tale of an FTSE 100 business that was run like a start-up, with a tiny circle of people at the top ruling the roost and setting the nasty tone of the company’s wider culture.

Justice Hildyard, the British High Court judge who oversaw the civil case between H.P. and Lynch before he was extradited to the U.S., described this group as a “cabal.” Hildyard found that Lynch and his “cabal” did indeed commit fraud by overstating Autonomy’s revenue and lying to the City of London about Autonomy’s figures. But Hildyard’s extensive, detailed judgment also said H.P. would have bought Autonomy anyway, even had it known the accurate sales figures. (It did a mere 18 days of due diligence on the transaction.)

Lynch, meanwhile, blamed the ineptitude of H.P., the harsh U.S. justice system, the unfairness of the U.S.-U.K. extradition treaty, a misunderstanding of the differences between global accounting systems … the excuses went on and on. This was despite the overwhelming evidence to the contrary: the forensic analysis of the accounts, the 30 witnesses who testified at the trial, the whistleblowers who had their lives destroyed by speaking out.

As to why Lynch was acquitted when his own chief financial officer was sentenced to five years in prison, the tycoon admitted it was because he had enough money to sustain a vigorous legal defense for years on end. The tragic irony is, had he lost that case, Lynch would likely still be alive today.

Katie Prescott is the technology-business editor at The Times of London and the author of The Curious Case of Mike Lynch: The Improbable Life & Death of a Tech Billionaire