eric campbell: it's a fight to take down the world's biggest strong man. maria pevchikh: the ultimate victory from us would be russia without vladimir putin. eric campbell: and it's led by the man who claims putin tried to kill him. alexei navalny has flown back to a prison cell and branded president putin the world's biggest thief. can navalny defeat putin? can he even survive? leonid volkov: he is in custody of the very people who tried to poison and kill him just less than six months ago. arkady ostrovsky: here is a guy of extraordinary courage. it's an absolutely archetypal myth, a hero fighting a tyrant. ♪♪♪ [crowd chanting in russian] eric: in the depth of winter, russia is stirring. since late january, protests have broken out across the country, sparked by the arrest of alexei navalny, who the kremlin insists is a nobody. but thanks to this nobody, people are calling their president a thief. natasha romi: now the crowd is moving to matrosskaya tishina. that's the prison where aleksei navalny is now being held at. eric: natasha romi is a young mosco

eric campbell: it's a fight to take down the world's biggest strong man.ia pevchikh: the ultimate victory from us would be russia without vladimir putin. eric campbell: and it's led by the man who claims putin tried to kill him. alexei navalny has flown back to a prison cell and branded president putin the world's biggest thief. can navalny defeat putin? can he even survive?

eric campbell: it's a fight to take down the world's biggest strong man.hikh: the ultimate victory from us would be russia without vladimir putin. eric campbell: and it's led by the man who claims putin tried to kill him. alexei navalny has flown back to a prison cell and branded president putin the world's biggest thief. can navalny defeat putin? can he even survive?