A few days ago, Russian political prisoners started vanishing from their prison colonies: Their lawyers would come to see them only to be told their clients were no longer there. The disappearance of an inmate is often bad news — it can mean a move to a more remote colony, illness or death. But as the number of “missing” prisoners grew, in the Russian dissident community a mounting sense of anticipation replaced the concern. “A trade,” a prominent Russian in exile posted on his Facebook page, without bothering to explain the reference. “Definitely a trade,” posted a young Russian activist in exile, a day later. “I am hopeful and I’m afraid to say the word,” posted another.

On Thursday, Russia released the Wall Street Journal reporter Evan Gershkovich, along with 15 other inmates. In exchange, Germany, the United States, Slovenia, Norway and Poland together released a total of eight prisoners, including the Russian assassin Vadim Krasikov. It was the largest and most complicated prisoner swap in this country’s history. It was also the largest such bargain the West has ever struck with Russia, a country whose legal system is designed to punish opponents of the regime and to generate hostages.

The story of this exchange began a year before Gershkovich’s arrest, in late January 2022. Christo Grozev, an investigative journalist living in Vienna, was strolling along Silver Lake Reservoir in Los Angeles with Maria Pevchikh, a leading figure in the anti-corruption movement started by the Russian opposition leader Aleksei Navalny.

Grozev, tall and lanky, moves with an awkwardness that suggests a boy who grew too fast. He sometimes forgets his backpack in cafes and he is peculiarly open for someone in his line of work. Pevchikh, who is a good two heads shorter, is organized, relentlessly logical, suspicious of strangers and careful with her words. The two had first connected after Grozev reached out to Navalny on Twitter. Navalny had survived a poisoning attempt that very nearly took his life. Grozev thought he might have identified the people who had done it.

Along with the producer Odessa Rae and the director Daniel Roher, Grozev had recently left Ukraine after offending too many powerful people. Together, the three wanted to come to Germany, where Navalny was recuperating, to make a movie about him and his failed assassins.