MOSCOW As the Kremlin clock inched towards midnight and the ice-bound river beneath their feet melted, a group of Russians silently stood on the bridge where Boris Nemtsov, the Putin critic and opposition leader, was killed nearly a year ago.
"This is about remembering," Boris Kazadayev, 73, part of the small crowd, told Reuters. "If there is no collective memory, the country won't have a future."
Moments later, a snow plough mounted the pavement forcing the crowd to the kerb. Two trucks then reversed within inches of people's backs and trapped them before dumping piles of snow around them.
"Nemtsov Bridge" - activists' nickname for the spot where the Putin opponent was shot dead on Feb. 27 last year - has become the scene of a cat-and-mouse struggle between the authorities and the liberal opposition who want to honour a man some Russians say the Kremlin would rather forget.
Supporters bring flowers for a makeshift shrine; the authorities sweep the site clean; his supporters rebuild. It's a sequence that has played out repeatedly, in all weathers, for at least 300 days.
"It is a model of peaceful resistance that is unique for modern Russia," said Olga Shorina, a Nemtsov ally.
"It has become a symbol of the fact that there's a desire for an alternative."
Activists say they will continue until a plaque is erected on the bridge to honour Nemtsov, a former deputy premier turned tenacious opposition leader. The authorities have refused.
Some activists also want the bridge to be renamed after him. That too has been rejected.
In a country where the Soviets air brushed people out of history but immortalised their heroes by burying them at the foot of the Kremlin wall or, in Vladimir Lenin's case placed him in a mausoleum on Red Square, the battle is seen by some as one for Russians' memories that could help determine their future.
"The authorities are doing everything they can to ensure Russians forget about my father," Zhanna Nemtsova, 31, told Reuters. "Their aim is not only to control the state but also to control people's minds and hearts."
The nearly year-long standoff has had an unexpected consequence: The spot where Nemtsov was murdered has become a unique if modest rallying point for the liberal opposition in what they say is an otherwise bleak political landscape.
Passers-by stop to look, opposition-minded Russians gather there to exchange ideas, and the Russian flag can sometimes be seen defiantly flying, visible from Red Square.
"It's an island of freedom in a zombified country," said Sasha Chernyavsky, a 29-year-old DJ.
The location, so close to the Kremlin's terracotta walls and the phantasmagorical onion domes of St Basil's Cathedral, packs rare symbolic punch.
"We will not allow, in the centre of Russia, in the very heart of Moscow, next to the Kremlin, for a bridge to be named after a person who always supported the interests of America and spat on the interests of Russia," SERB, a nationalist group that vandalised the site at least twice, has complained.
In flux due to its regular destruction, the makeshift memorial has a few constants: flowers, icons, candles, written tributes and portraits.
"I don't like being shot in the back," reads one note, a reference to the fact that Nemtsov was shot from behind.
Each day at 23.31, the time Nemtsov was killed, his supporters observe a minute of silence.
Nemtsov, 55, was killed as he walked home with his girlfriend after dinner. Putin, after his murder, described him as one of his fiercest critics.
Nemtsov helped found the country's main anti-Kremlin movements and spoke at opposition rallies. He had authored an excoriating report into Putin's tenure, and shortly before he was killed was working on a report examining the Russian military's role in Ukraine.
Revered by his supporters as an unpretentious man of the people, some Russians disliked him, associating him with the 1990s, a period of food shortages when he was a deputy prime minister.
"What did he do for Russia?" Valentina Arsentieva, a reader of pro-Kremlin lifenews.ru, wrote the day after his killing.
"We were eating animal feed in the 1990s while THEY were selling Russia out to the West."
State TV largely ignored him in recent years. But his profile in the 1990s meant he remained a household name.
Within hours of his murder, hundreds of Russians flocked to the scene to leave flowers.
The authorities downplayed his significance.
Putin's spokesman cast Nemtsov, once spoken of as a contender to succeed Boris Yeltsin as president, a job Putin got, as "quite an average citizen" who was no political threat.
Putin said something similar about reporter Anna Politkovskaya after she was murdered on his birthday in 2006.
BATTLE OF THE BRIDGE
What looked like a campaign to erase Nemtsov's memory soon began.
A month after his murder, activists arrived to find that the flowers and other tributes had vanished. It is a routine that has been repeated, by conservative estimates, at least 15 times. Some say the real number is double that.
The first clearance, before the end of the 40-day mourning period observed by Russians, caused particular offence.
"Some people told me they felt as if Boris had been killed a second time," said Olga Lehtonen, 38, who would later protect the site.
Since that first clearance, on March 28, around 30 unpaid volunteers have mounted a round-the-clock vigil.
Sometimes braving temperatures of minus 20 Celsius, some have been arrested and assaulted.
"We don't have any other avenues to express ourselves," said Andrei Margulev, who spends 26 hours on the bridge a week. He was arrested for reciting poetry there in September and fined 10,000 roubles ($130.93) by a court.
Pro-Kremlin activists have trashed the site at least twice, throwing eggs, smashing tributes, and trying to urinate on the shrine.
But it is the Moscow authorities who have regularly sought to remove clues that Nemtsov was killed there.
They say they want the area to stay clean, that the Stalin-era bridge on which amateur German pilot Mathias Rust famously landed a small plane in 1987, is a monument of cultural importance, and that the shrine is illegal.
Yuri Ivankov, head of the city's bridge maintenance division in a statement spoke of "banal vandalism." His office declined to comment for this article.
Putin said last year he saw no problem with people leaving tributes. He promised to speak to Moscow's mayor to ensure people were not prevented from doing so. Activists said the clearances became less frequent after Putin's words but continued nonetheless.
When asked about a plaque for Nemtsov, Putin cited a rule stating that 10 years must first pass.
Nemtsov's supporters say Putin and Moscow's mayor could easily bypass that rule as was done for Venezuela's Hugo Chavez who had a street named after him. The mayor's office did not respond to written questions about the proposal.
BATTLE FOR THE FUTURE
Nadezhda Prusenkova, a colleague of slain reporter Anna Politkovskaya at the Novaya Gazeta newspaper, said the way the Kremlin was handling the situation was "a test for the authorities and for society."
"It is a defining moment for self-identification," she said.
More than 21,000 people have so far signed an online petition supporting a plaque.
"Monuments have an importance not only for the past but also for the future," said Alexander Cherkasov, a historian at human rights group Memorial.
"We are choosing from a huge number of events and people to build our futures looking back at certain reference points."
Ilya Yashin, an opposition politician, said that was why there was so much official resistance to the idea of commemorating his murdered friend.
"Nemtsov as a symbol was and is very dangerous for the Putin regime," said Yashin. "But the more they destroy his memorial, the brighter a symbol he will become."
Meanwhile, the investigation into his murder has run into the sand with police charging a group of Chechen men with carrying out the killing for cash. No other motive has been suggested.
Police have named a fugitive Chechen as the alleged mastermind, but Nemtsov's supporters say he was only a low-level figure and that a cover-up is underway.
They want Ramzan Kadyrov, the leader of Chechnya, to be questioned.
Kadyrov has said talk of his being a suspect is nonsense.
The defenders of "Nemtsov Bridge" say they will not give up. They plan to march to the bridge on the first anniversary of the murder this month.
Dmitry Gudkov, the only liberal opposition lawmaker in the Russian parliament, says a successful outcome to the battle of the bridge would be significant.
"It would be a signal to society that political terror is unacceptable," said Gudkov.
Olga Lehtonen, one of the bridge's volunteers, said the campaign was as much about remembering a man as politics.
"We only want a small plaque," said Lehtonen, holding a piece of A5 to show its size. "How can that bother anyone?"
($1 = 76.3775 roubles)
(editing by Janet McBride)