Transcript for ‘Citizen X’ and Hong Kong protesters’ battle for freedom
Reporter: Into the heart of a growing rebellion. Through the Gates of a major college campus, littered with trash, barricaded with chairs. And a makeshift check point for all who dare enter Hong Kong's You want to look in my bag? Reporter: As we move through the college quarters, the air is thick with the steal stale smell of beer. But they aren't drinking it, they're pouring it out. And everywhere we turn, it becomes clear what the bottles are used for. We walked into a bomb-making factory. Turning beer bottles into molotov cocktails to use against police. Have you been testing them over here? Yes. This is actually my first time. Reporter: Their practice range, an olympic-sized pool. We've been covering the protests in Hong Kong since they began and seen this modern metropolis descend into a city of fire. As local citizens fight back against China's growing influence and control. Just stay back. Back in August we met this man. You won't stop. We won't stop. Reporter: He's a student, but I can't say what he's studying. He's young, but I'm not allowed to tell you his age. He's a protester, but I won't give you his name. He fears for his safety, so I've dubbed him citizen X. I'm born and grown in Hong Kong. I love how special it is. I love the freedom that we are enjoying, and I don't want Hong Kong to become just like another city of China. Reporter: We interviewed him at a secret location, hiding his face and disguising his voice. Going beyond wooden sea on TV into the homegrown dissident. Some people say we are a group of people chosen by this era, chosen by history. This is our home, and we have to use every measure to us to protect our home. Reporter: He's one of tens of thousands of students in Hong Kong forced to decide what is freedom worth and what are you willing to sacrifice to get it. Are you willing to sacrifice your liberty floor? I'm willing to be put in a jail for months. I'm not mentally prepared for that. Reporter: What is your goal? Are you trying to get Independence? We are trying to get freedom and democracy. Reporter: It's 30 years since students first dared the communist party. Tiananmen square, one image seared into the global conscience. One lone man defiant against a column of tanks and an entire system. Hong Kong was free from those shows of force until 1997 when Britain handed control of the city to China. Beijing promised to let Hong Kong govern itself for 50 years, but it's been an uneasy compromise. This year, tensions erupted when a law was proposed to allow citizens to be extradited to mainland China to stand trial. It never passed but lit a fuse. Hong Kong residents were angry, accusing China of rolling back their freedoms, and hostility between police and protesters rapidly escalated. Citizen X is part of the vanguard of the protest movement. They call themselves the valiants, or the brave. Those who hold the front line and forcibly confront police. We have no other options but to win. This is our home, and we have to use every measure for us to protect our home. Reporter: We met up with X again ahead of another protest. He and his group began by coordinating at a shopping center, discussing tactics, part ninja, part anime warrior. Having no leader in this movement is the key essence. The government cannot predict, the police cannot predict. Reporter: It's like an organic beast. We head out to the front line. Police are going to charge let's go off to one side. Let's hunker down over here. Tear gas canisters right behind we try to stay with X, but in the swirl of tear gas, rubber bullets and chaos, he's gone. Okay. Tear gas. Move, move. These are just crazy scenes here in central Hong Kong. Everyone's running. Move, let's go to the side. One month later, I ran into X at another protest. No time to talk. Another time and X takes off, disappearing into the mob. It will be the last time I saw him in person. . Reporter: Move back. We're prepared to die. The stronger our passion is the stronger we will be. Reporter: By November, the violence becomes deadly. Another protester shot with a live round. And an argument with protesters leads to a man being doused and set alight. A new tactic emerges, protesters occupy several college campuses, paralyzing the city. Inside the polytechnic university, students show me how they're fortifying the school. And then you light up -- Reporter: But the hardcore battle prep is hereby N that molotov cocktail factory and training ground. Within days, the police attack. The and the school is under siege. Rubber bullets flying in and tear gas. Police move in on the campus, so protesters set fires in walkways, on police-armored vehicles, and a massive blaze right on those front steps to block the way. Many protesters try to escape, but most are caught and arrested. In the confusion, we slip back inside the campus where we found hundreds of students stuck and demoralized. Like there's absolutely no way out. Knowing that we can go nowhere then we are quite helpless. What are we supposed to do? Just go out and get shot by rubber bullets and tear gas? Or just wait here and starve and die? Reporter: If you had one final message to the outside world, what is it? We need help. Reporter: Within days, most of the students surrendered or got away. Then suddenly, last night, we heard again from citizen X in an audio message. He says he was at the battle of poly U, and that he was beaten and arrested. I've never experienced the weight, the burden of such a battle, such a warfare, I would say. It comes with immense pressure. We need to regain our power. We need some more time to reorganize another wave of movement that can really threat then regime that is so corrupted. Reporter: Beijing is watching what happens here, closely. But the question remains, is anyone listening? This is our responsibility. So we cannot escape from this. Because, if we don't do it, all of Hong Kong loses. Up next, the undecided and
This transcript has been automatically generated and may not be 100% accurate.