(CNN) -- At 10 Friday morning, the Russians will give Frank Hewetson the best holiday gift of all: a stamp in his British passport that will allow the Greenpeace activist to leave the country and return home to his family.
The exit visa will put an end to Hewetson's chilling saga that began in September in the icy waters surrounding an Arctic oil rig.
He was among 28 protesters and two journalists aboard the Greenpeace ship Arctic Sunrise who were arrested by Russian authorities and thrown in jail. Hewetson, 48, was on the helicopter deck of the ship, taking in a full moon and a sunset on that September evening. It was a sight to behold in the Arctic.
Amid the breathtaking beauty, he saw on the horizon what looked like a little wasp buzzing around, getting bigger and bigger. Suddenly, a massive helicopter swooped down, the monstrous gusts of winds knocking Hewetson off his feet.
Russian paratroopers stormed the Greenpeace ship. It was frightening and Hewetson felt queasy, his just-eaten dinner barely digested.
Five days later, he found himself locked up in a Russian prison that seemed a mix between a joke and a Cold War-era novel by John le Carre.
It was dilapidated and rat-infested. Some windows were broken and the central heating didn't work everywhere.
"It was like stepping back in time," Hewetson said.
He'd worked for Greenpeace, perhaps the world's best known environmental activist group, since 1989 and on campaigns across the world. He joined the mission to protest the rig owned by Russian company Gazprom because he firmly believed oil companies had to be stopped from drilling for fossil fuels in the Arctic.
Suddenly, his life seemed severed from all that he loved -- his wife and two children in London, his dog Pluto and his passion for ping pong. Russia had not only jailed him but he, like the other Arctic 30, as they became known, were facing charges of piracy so serious that he was looking at a possible 15 years behind bars.
At home in England, those kind of charges meant the authorities had a heap of evidence against the accused.
He felt "pretty damn desperate," he said Thursday. "That was a very hard night for me in prison."
The charges were later reduced to "hooliganism" which still carried a penalty of seven years in jail.
Each day, the minutes ticked slowly.
Hewetson passed time by reading, though it took a long time for the prison to receive books sent by family and friends and even longer to add them to the library. Author Terry Pratchett's light-hearted writing struck the right chord.
"One had to pace one's reading," he said, "because staring at the ceiling lying in your bunk with nothing to take your mind off your immediate predicament was not a good place to be."
The cell was about 18 feet by 7 feet and contained three men -- Hewetson and two inmates already there on criminal convictions. The floorboards had rotted out, the window, busted. A toilet was separated by thin, wooden panels -- a call of nature at dinner hour was not appreciated by other cellmates. The light was on 24/7 and the air was thick with cigarette smoke, something that bothered Hewetson, a nonsmoker.
Hewetson got on famously with his two cellmates, a fact that is fundamental, he said, to enduring prison life. He discovered through a strange form of lingua franca the reason for incarceration of his cell mates. They played chess together once Greenpeace managed to send across a set.
"During these games I found out, quite slowly, that 'S' was in for double manslaughter and 'V' was in for gangland violence," Hewetson said, referring to his cellmates. "Despite the differing reasons for our incarceration we became very close friends."
He spent 23 of 24 hours every day in that cell. He was allowed one hour a day of solitary exercise in a small pen. He dreamed of playing ping pong, a game he loves enough to list as a hobby on his Greenpeace profile.
Another lifesaver was a Russian human rights activist who visited him regularly. The British prisoners nicknamed her Mrs. Tiggy-Winkle because she (rather unkindly, he said) resembled the hedgehog washerwoman in a Beatrix Potter tale.
Hewetson, like everyone else, lost a lot of weight during his imprisonment. The food, he said, was truly awful.
"The evening meals quite often contained fish heads. This mainly got flushed away as it was unpalatable even when really hungry."
The ordeal ended last week, when a sweeping amnesty program in Russia allowed the Arctic 30 to go free.
Russian President Vladimir Putin has been generous with "get-out-of-jail free cards" of late. The amnesty law freed business executive Mikhail Khodorkovsky and two members of Russian punk band Pussy Riot, jailed for a performance critical of Putin.
Hewetson said he was relieved.
"I think the Russian Olympics had quite a bit to do with it," he said about the upcoming 2014 winter games in Sochi.
Hewetson hopes to leave for St. Petersburg Friday morning. In the meantime, some prison habits have been hard to shake. He does his own laundry, cooks his own noodles with a boiling ring in his hotel room and eats kasha (porridge) every morning.
"Such activity before prison would have been pretty alien to me," he said.
Despite prison, Hewetson seems committed to Greenpeace. He spoke Thursday about how dangerous drilling for oil in the Arctic is to the environment.
But for now, he just wants to get back home to London, to his family. He wants to light a wood-burning stove and brew a good cup of tea. And take his dog for a long walk.