Elizabeth Holmes was once described as the most exciting young entrepreneur in Silicon Valley. By 2014 she was being called the world's youngest self-made female billionaire, her company Theranos was valued at around $9 billion, and she was on the cover of magazines presenting a vision of healthcare that seemed genuinely revolutionary. Eight years later she was convicted of fraud, and in May 2023 she reported to federal prison to begin an 11-year sentence.

A new documentary, You Can See Everything, which premiered as a surprise inclusion at the Telluride Film Festival, captures Holmes during the final 34 days before she walked into prison. Its trailer has left viewers stunned, offering an intimate look at the woman behind one of the most spectacular corporate collapses in modern history.

So what exactly did Elizabeth Holmes do, and why is she in prison?

Holmes founded Theranos in 2003 at the age of 19, having dropped out of Stanford University. The company's central promise was transformative: that its technology could conduct hundreds of medical tests using only a tiny amount of blood collected from a simple finger prick, rather than the conventional method of drawing blood from a vein. The implications for healthcare, if true, would have been enormous, making testing faster, cheaper and more accessible.

The promise attracted enormous investment. Among those who put money into Theranos were media billionaire Rupert Murdoch and members of the Walton family, the dynasty behind Walmart. By 2014, the company was reportedly worth around $9 billion and Holmes was celebrated as a visionary.

But questions about whether the technology actually worked had been circulating among experts for years. Dr Jeffrey Flier, the former dean of Harvard Medical School, met Holmes in 2015 and came away with serious doubts.

"She was self-assured," he said, "but when I asked her several questions about her technology, she didn't look like she understood."

In 2015, a whistleblower raised concerns about the company's claims internally, and the Wall Street Journal published a series of damaging reports. The investigation alleged that Theranos was not actually using its own technology to conduct the vast majority of its tests. Instead, it was using conventional machines made by other manufacturers, while questions were also raised about the reliability of some test results.

The company collapsed. Holmes was arrested in 2018 and charged with wire fraud and conspiracy to commit wire fraud. She denied any wrongdoing throughout.

Her trial, which was highly publicised, saw prosecutors argue that she had deliberately misrepresented both the capabilities of the technology and the company's financial position in order to secure hundreds of millions of dollars in investment from wealthy backers. Her defence pointed partly toward her former romantic partner and business associate Ramesh "Sunny" Balwani, arguing he had played a significant role in the company's operations.

In January 2022, a jury convicted Holmes on four counts related to defrauding investors. She was acquitted of separate allegations concerning patients. In November 2022 she was sentenced to 11 years and three months in federal prison.

Balwani was prosecuted separately, convicted on all counts and received a sentence of almost 13 years.

Holmes reported to prison in May 2023. The documentary You Can See Everything captures who she was in the weeks before she did.