No one has exposed more Russian spies and assassination plots than investigative journalist Christo Grosev, first for Bellingcat and more recently for The Insider.

His reportage has earned him the admiration of those who value freedom of expression and the rule of law, but behind Kremlin walls the response to his work has been rather different. Officials there in effect declared him an enemy of the state after he exposed the scheme to eliminate Russian opposition leader Alexei Navalny by dosing him with the deadly nerve agent Novichok. The Oscar-contending documentary Antidote reveals how Grosev became the prey of a Bulgarian spy team dispatched on Kremlin orders to abduct or assassinate him.

“I was not really worried about myself. I was worried for my family,” Christo told us in a conversation after a screening of Antidote as part of Deadline’s virtual event series For the Love of Docs. “There were continued operations of this team, of this spy ring, that I wasn’t aware of, including breaking into my apartment in Vienna while my son was in his room. And moments like this, when you retrospectively learn about them, they really make your blood curdle and be extremely angry.”

Director James Jones (left) and journalist Christo Grozev attend the 'Antidote' premiere at Tribeca Festival in New York City.

Director James Jones (left) and journalist Christo Grozev attend the ‘Antidote’ premiere at Tribeca Festival in New York City.

Arturo Holmes/Getty Images for Tribeca Festival

The film – winner of awards at Tribeca, the Hamptons International Film Festival, and The Hague Movies that Matter Festival – is directed by James Jones (Chernobyl: The Lost Tapes). The project took twists and turns worthy of a John le Carré novel.

“When we started, [the idea] was kind of lifting the lid on Putin’s poison program. We had this whistleblower who’d developed Novichok, which was used to poison some of Putin’s biggest enemies like Alexei Navalny,” Jones explained. “And then as time went by, it morphed into more of an ongoing story about the risks you take in standing up to Putin, what sacrifices you make in telling the truth about Putin’s Russia. And then about halfway through, obviously Christo got the news from American law enforcement that there was this plot to follow him around the world, but also to kidnap or kill him.”

Jones added, “His world was turned upside down and, credit to Christo, we carried on filming through that period, which was incredibly unsettling and discombobulating for him. And it felt surreal, to be honest. It felt like we were living through a spy film.”

Just like a good espionage movie, this tale came with an appropriately sinister baddie (in addition to Putin): Jan Marsalek, a fugitive Austrian businessman turned alleged embezzler, with ties to Russian intelligence. It was Marsalek who allegedly coordinated the maneuvers of a group of Bulgarian agents tasked with tracking Grosev and other targets. The six Bulgarians were nabbed in the UK and tried on espionage charges.

“[Marsalek] was kind of the Bond villain who’d escaped to Russia, lived this kind of fantastical life involving honeytraps, all these things. It seemed too rich to be believable,” Jones commented. “Then it all came to a head in the trial at the Old Bailey in London, and we saw 200,000 text messages between Jan Marsalek and this spy ring, and it was laid out in granular detail, hour by hour, minute by minute.”

Investigative journalist Christo Grozev in 'Antidote'

Investigative journalist Christo Grozev in ‘Antidote’

Frontline/Passion Pictures/Bellingcat

The shifting plot necessitated a rethinking of the name for the documentary. One early thought had been to dub it Poison, but other options were considered.

“One of the working titles for the film was in fact Killing Christo,” Grosev told us. “I do think that Antidote carries at least that ambivalence between optimism and pessimism. And I’m grateful that we changed it to this.”

Those who have seen the Oscar-winning documentary Navalny will recall that the Russian opposition leader survived his August 2020 poisoning attack, went on to work with Grosev to uncover those responsible for the plot as he recuperated in Germany, then made the fateful decision to return to Russia, whereupon he was immediately arrested and imprisoned.

Antidote explores how Grosev became involved in efforts to win Navalny’s freedom as part of a secret negotiation between the Biden administration, Russia, and Germany. Just as success seemed within reach, Navalny’s death was announced in February 2024.

Alexei Navalny in Moscow's City Court on May 24, 2022

Alexei Navalny in Moscow’s City Court on May 24, 2022

Contributor/Getty Images

“He was killed while he was serving a prison sentence in Russia. And what was my hope that in the course of the filming [of Antidote], we were going to capture the moment when he gets swapped, when he gets released, because I was working on a backchannel for more than a year on that possible release,” Grosev shared. “Ultimately, we lost him. We had Putin decide, as it appears to be the case, to dispose of him before an actual swap was agreed to.”

After Navalny’s demise at age 47, Grosev shifted his efforts to try to earn the release of another political prisoner held in Russia, the Russian British author and activist Vladimir Kara-Murza. That prisoner swap would have a happier ending.

L-R Russian opposition figures in exile Ilya Yashin, Yulia Navalnaya and Vladimir Kara-Murza speak at an anti-war demonstration on November 17, 2024 in Berlin, Germany.

L-R Russian opposition figures in exile Ilya Yashin, Yulia Navalnaya and Vladimir Kara-Murza speak at an anti-war demonstration on November 17, 2024 in Berlin, Germany.

Axel Schmidt/Getty Images

Kara-Murza is now living with his wife in Virigina. Grosev took up residence in the U.S. after having to abandon his home base of Vienna when the Kremlin plot against him came to light. He may shift countries again, as the Trump administration becomes much cozier with Russia than was the Biden administration. The reality is that crossing Putin comes at a significant price.

“Dealing with the Kremlin, there is to all intents and purposes like a heart of darkness when it comes to journalism and truth,” Jones noted. “And so it felt like an important film, and I’m really proud and grateful to Christo that he allowed us to carry on documenting it through some very difficult times.”

Watch the full conversation in the video above.

For the Love of Docs continues next Tuesday with a screening of Marlee Matlin: Not Alone Anymore, followed by a conversation with director Shoshannah Stern and producer Justine Nagan. RSVP for that event by clicking here.