In February 2025, the body of journalist Viktoriia Roshchyna was finally returned to Ukraine after months of uncertainty. She was one of 757 Ukrainian casualties handed over by Russian authorities as part of an exchange of prisoners and the dead.

Roshchyna had disappeared in the summer of 2023 while reporting from the Russian-occupied territories in Ukraine. When her body was examined, parts were missing: her eyeballs, her brain, her larynx – possibly removed to conceal the signs of how she died. Preliminary forensics suggest “numerous signs of torture”, according to the Ukrainian prosecutor.

Viktoriia – or Vika, as her colleagues called her – had spent part of her captivity in the prison of Taganrog, in southern Russia, sometimes referred to as the “Russian Guantánamo”. It is a place where Ukrainian civilians and prisoners of war are held, interrogated and broken. Later that year, the deputy head of Russia’s military police wrote to Roshchyna’s father to say she had died on 19 September.

A young and determined reporter, Viktoriia was one of the only journalists willing to enter the occupied territories to understand what had happened to the thousands of Ukrainian civilians abducted and detained in secret. She was investigating a system of disappearances. Then she became part of it.

As we at Forbidden Stories – the organisation I founded – began to find out what happened to her, it quickly became clear that it was not a job for a journalist working alone. Russia was inaccessible – too dangerous, too controlled. The system she was investigating was designed to leave no trace. Continuing her work required something different; it required many of us.

At Forbidden Stories, we have brought together journalists from multiple countries to pursue the investigation that she had started. We worked with Ukrainian reporters from Ukrainska Pravda, with Russian journalists in exile, including at the publication iStories, and with others across borders, including the Guardian and the Washington Post. We spoke to former detainees, some of whom had shared cells with Viktoriia, and pieced together fragments of a system that was never meant to be seen.

Using open-source data, satellite imagery and testimonies, we rebuilt parts of the prison in 3D and traced her path through a network of detention sites. Slowly, collectively, we made visible what she had risked everything to expose.

None of this would have been possible alone. But working together does not come naturally to journalists. We are trained to work alone – to hold on tightly to our information in what is a highly competitive industry. Trust has to be built, across languages, cultures and editorial traditions that do not always align.

When dozens of journalists work on the same investigation, each piece of information is scrutinised, challenged and verified. What some may fear – that collaboration increases the risk of error – is, in fact, the opposite. More reporters ultimately means stronger reporting.

Each journalist brings access, context and sources that others do not have. The final story is richer, more precise and, as a result, more difficult to dismiss. This requires effort and it requires humility. It means, as well, setting aside egos and accepting that the story no longer belongs to one person.

The impact is clear. From the Panama Papers to the Pegasus project, collaborative investigations have exposed systems that no single newsroom could have uncovered alone. They have also led to real consequences: individuals responsible for Viktoriia Roshchyna’s detention have since been placed under EU sanctions after the publication of the Viktoriia Project.

Working alone today means being vulnerable, especially in environments where threats are organised, transnational and often backed by state power. Ahead of World Press Freedom Day on 3 May, we conducted a survey of more than 200 journalists under threat in 53 countries. It offers a clear picture of the threats that journalists face and what actually protects them. Traditional safety mechanisms offer little protection. Most do not report threats, or do so without result. In many cases, after all, those responsible are public officials.

But one finding stands out. Nearly 70% of those journalists agreed that what those targeting them fear the most is coordinated, cross-border investigations – far more than NGO statements or legal action. In other words: if someone wants to silence a story, the answer is to make it bigger.

We see this logic at work. Journalists increasingly share their material in advance, collaborate across borders, and ensure their reporting can continue if they are threatened, jailed or worse. It has become a way to protect ourselves. Leonardo G Ponce, an Ecuadorian journalist who reports on organised crime, has secured his ongoing investigations with Forbidden Stories so that if anything happens to him, his work will be pursued by dozens of journalists. He also makes this known publicly.

That is often enough to make people hesitate. For decades, journalism was built on the image of the lone reporter. Today, that model is breaking down.

Viktoriia Roshchyna tried to document a system of disappearances on her own. To uncover what happened to her, it took dozens of journalists. She was meant to disappear. Instead, her story multiplied.

• Laurent Richard is a journalist and the director of the Forbidden Stories consortium