As Vladimir Kara-Murza faced a row of guards clad in black balaclavas and lined up against a prison wall in Moscow, the 42-year-old remained baffled at the fate that awaited him. 

It was Aug. 1.

He had been in a Russian prison for more than two years, but in the previous five days he became convinced he would either be hastily executed or that Russia's courts would extend the 25-year sentence he was already serving for treason and spreading false information.

It wasn't until Kara-Murza was led onto a coach bus parked outside, and peered through the dim lighting at the other passengers onboard, that he was able to piece together what was happening.

"In every row, I see more men in black balaclavas covering their faces … but next to each of them I saw a friend, a colleague, a fellow political prisoner," he told CBC News this week, during his first interview with Canadian media.

"That was the moment I realized what was going on, because there could only be one reason why all of us would be on the same bus together."

The group was en route to the airport, and eventually to Turkey, where they would be freed in the largest prisoner swap between Russia and the West since the Cold War.

Historic prisoner swap

On Aug. 1, after years of political negotiations involving several countries, including the United States, Germany and Poland, Kara-Murza was freed from Russian prison along with 15 others, including Canadian-U.S. citizen Paul Whelan and Wall Street Journal reporter Evan Gershkovich.

In exchange, Russia received eight of its citizens convicted abroad, including Kremlin hitman Vadim Krasikov, who gunned down a former Chechen militant in Berlin in 2019.

Kara-Murza, who also holds British citizenship and was granted honorary Canadian citizenship while imprisoned in Russia, is currently on a whirlwind tour of Europe, visiting five countries in 10 days, to meet with lawmakers and supporters. 

He spoke to CBC News in Berlin, where he also met with German Chancellor Olaf Scholz, who played a key role in negotiations. 

During the hour-and-half interview, Kara-Murza recounted his arrest, the months he spent in solitary confinement and the surreality of freedom. 

WATCH | Prisoners were in the dark about swap until final moments: 

Freed Russian opposition activist Valdimir Kara-Murza describes dramatic prisoner exchange

Vladimir Kara-Murza, a well known Russian opposition activist who was recently part of a high-profile prisoner exchange that also included Wall Street Journal reporter Evan Gershkovich and Canadian-U.S. citizen Paul Whelan, describes the moment he was about to be free.

Kremlin target

Long before Kara-Murza was arrested on April 11, 2022, outside of his home in Moscow, the father of three had been a high-profile target of the Kremlin.

An author and journalist, he frequently travelled abroad, speaking with politicians in the West — including in Canada's Parliament — about the need for sanctions against Russian human rights abusers. 

Kara-Murza had been persecuted and poisoned, nearly dying twice. Despite the great risk, he kept returning to Moscow, including in the initial weeks after Russia launched its full-scale invasion of Ukraine. 

"How could I call on my fellow Russian citizens to stand up and resist Putin's dictatorship if I didn't do it myself?" he said. "What would all my convictions, all my appeals, be worth if I was sitting somewhere far away?"

A year after his arrest, Kara-Murza was convicted of treason and spreading false information in a trial he said resembled one of Joseph Stalin's show trials in the 1930s.

He was and sentenced to 25 years in prison and transferred to a facility in Siberia, where he spent 11 months in solitary confinement. He estimated the cell measured two by three metres, and featured a small window — just under the ceiling, with metal bars — and a bunk bed. 

He wasn't allowed to use the bed between 5 a.m. and 9 p.m., so he would either walk around in circles or sit on a stool. When that became too uncomfortable, he would move to the floor. 

"It's very difficult to stay sane [in those circumstances]," he said. "After about two weeks … you stop understanding what's real and what's imagined. You start to forget words. You start to forget names. I mean, you just sit there and stare at a wall."

He was given a pen and paper for 90 minutes a day, which he could use to write letters or respond to the mail he received, which was frequently censored by prison officials. 

WATCH | Kara-Murza describes tedium of solitary confinement: 

Released Russian opposition activist describes solitary confinement in Siberia

Russian opposition activist Vladimir Kara-Murza, who was recently part of a high-profile prisoner exchange that also included Wall Street Journal reporter Evan Gershkovich and Canadian-U.S. citizen Paul Whelan, describes what life was like in solitary confinement in Siberia.

With the small amount of money he had in a personal prison account he ordered a Spanish textbook, because he knew it was crucial in keeping his mind engaged. 

"One of the worst and most difficult things in prison is this constant feeling that you are just throwing away the precious time that you have in your life, because you do nothing," he said.

"It's important to do something constructive."

A sudden, unexplained move

On July 23 of this year, a prison official instructed him to sign a petition asking Russian President Vladimir Putin to pardon him. Kara-Murza refused to do so, but was baffled by the request. 

Five days later, a group of officers burst into his cell at 3 a.m., demanding he get dressed. 

"I was absolutely certain that I was going to be let out and be executed," he said. "But instead of the local woods, the prison convoy took me to the airport."

As he was escorted onto a commercial plane in Omsk, Siberia, he was confused, and after spending so many months in isolation, he was taken aback by seeing so many other passengers.

When he arrived at the notorious Lefortovo prison in Moscow, he assumed he would end up in court and charged with something else. Kara-Murza asked a prison official to notify his family and his lawyer that he had been transferred to Moscow, but the man refused.

"He looks at me and smiles and says … 'You have not been transferred to Moscow, you are still in Omsk.'"

"By this stage, I've completely given up trying to understand what's happened," Kara-Murza said.

There was no information released about his whereabouts, because the groundwork was being laid for the carefully co-ordinated prisoner swap. 

On Aug. 1, guards entered his solitary confinement cell and told him to put on civilian clothes. 

He pulled on his nightshirt and long underwear, which was a necessity in Siberia. On his feet were flip-flops that he used in the shower room. These were the only belongings he had. 

A prison guard scoffed at his attire. 

"I said, 'Look, man, I'm serving a 25-year sentence in solitary confinement in a maximum security prison in Siberia. Why would I need civilian clothes?'

"This is how I met with German Chancellor Olaf Scholz later that day: in my flipflops along with my nightshirt."

Once he was on the bus with the other prisoners, a security agent said they were headed to the airport. As they drove through Moscow in a police convoy, Kara-Murza looked out the tinted windows trying to absorb as much of the city as he could — it was unclear when he might be able to return. 

Oval Office on the line

Once the plane was in the air, the prisoners watched a screen showing a flight map, looking for clues as to where they were headed. Kara-Murza said they eventually realized they were going to Turkey. 

When the plane landed in the capital, Ankara, the prisoners were escorted off one by one onto another bus, where German agents with file folders and photos confirmed their identities. 

Having lost about 50 pounds in prison, Kara-Murza said he looked much different than his arrest photo, so the agents resorted to a series of personal questions in order to verify his identity. 

Once that was complete, he and the others were taken into a reception room, where sandwiches and cookies lined a table. 

A woman from the U.S. Embassy walked up and asked if he was Vladimir Kara-Murza.

"She handed me the phone and she said, 'The president of the United States is on the line, waiting to speak to you.'"

Kara-Murza, who hadn't spoken English in more than two years, said he "scrambled" to try and say thank you to President Joe Biden, who was in the Oval Office alongside Kara-Murza's wife and children.

"When I heard the voices, there are no words in any language that I know that can describe the feeling," he said.

WATCH | A mysterious flight and then a call from the U.S. president: 

Freed political prisoner Valdimir Kara-Murza on getting call from White House

Russian opposition activist Vladimir Kara-Murza describes receiving a call from the White House moments after arriving in Ankara, Turkey, as part of a high-profile prisoner exchange.

Surreal freedom

In the last month, Kara-Murza has reunited with his family, who live in the U.S., and met with world leaders. He anticipates visiting Canada again to thank Parliament for making him an honorary citizen.

"I accept it not for myself but on behalf of all of those people in Russia … who are unjustly imprisoned by Vladimir Putin's regime for having spoken out against the war in Ukraine."

He has resumed his work with the Free Russian Foundation, a Washington, D.C.-based non-profit that is in part focused on trying to ensure Russia can transition to a democracy, once Putin's grip on power eventually ends. 

While Kara-Murza's schedule is crammed with advocacy work, he has a hard time articulating how he has adjusted to his newfound freedom — because it hasn't really sunk in. 

"It still feels like I'm watching this from the outside," he said. "I was convinced that I was going to die in that Siberian prison."