Romania’s official Oscar entry for international feature, “Collective,” marks the first time the country has submitted a documentary to the Oscars.

Alexander Nanau’s story follows the 2015 fire at the Colectiv nightclub which killed 64 people and injured hundreds. Released on-demand Nov. 20 and in select theaters, Nanau’s trail takes him from the deadly fire to a healthcare crisis to the heart of political corruption within the Romanian government.

Nanau talked to Variety about how he pieced the documentary together and gathered interviews with whistleblowers as journalists uncover a scandal that rocked a country.

How soon after the Colectiv nightclub fire in 2015 did you have the idea for the film?

Oh, I didn’t. I was interested in understanding what’s going on because demonstrations had erupted, and there was a message by the younger generation of “Corruption Kills” that wanted to force the political class to reform. There was manipulation and kids were continuing to die in hospitals. It was clear that we were assisting in a lie.

Cătălin Tolontan started investigating the healthcare system, and I thought it would be interesting to follow and understand what was going on in society, through the eyes of an investigative journalist and investigative power. When I started the film I never knew where it would lead and what it was like to be there when a journalist finds information, verifies it and meets whistleblowers. It was such an adventure.

Did you have any idea where it would end at all?

I didn’t because it was all so new to me. I think that made me more desperate because I felt I wasn’t prepared and then it became about where to stop filming and when.

Everything was about hoping that you were making the right decisions and hoping that you were following the right characters.

It was always about staying alert and making sure I was responding in the right cinematic way. Every day, there was the question of ‘What is happening?’ and what was the best translation of that into cinematic language. I didn’t even know what the journalists were investigating when I began. We had to put that together ourselves before they trusted us.

Early on, you show the fire. Was there ever a thought of not showing it?

I had a lot of discussions around it with one of my closest collaborators, Mihai Grecea. He came on to the project and he was a survivor. He was one of the organizers working with the camera crew at the concert. He was in the fire, severely injured and it’s a miracle he’s alive.

At first, I didn’t want to use it. Then I asked myself if I would show gas chambers from inside if I had that footage, and that was a moral issue for me. I had to fight with myself and understand this footage. By showing it, it was the only way to show people how fast our lives can change.

Your subjects are the journalists and the victim sharing her story. How did you get them to trust you and open up?

The trust came because they understood our professional level and that we were very serious about what we were going to do and follow it to understand the wider context.

With Tedy and the victims, it is about how you approach people. They are smart people and they feel your intentions. I had to make them understand it was an observational documentary and we’d follow them for a long time, but it was important to share that Mihai was a part of that. They trusted me because they trusted him.

How did you land on the whistleblowers for this?

They came through Tolontan, but one, I understood was a doctor who wanted to talk. She was friends with a journalist. She had done a piece earlier where her voice and face were obscured, and it was a long process. But again, Tolontan trusted us and many of the whistleblowers trusted us.

In other cases, the most sensitive matter was the relationship between journalist and whistleblower, so we’d get calls saying a whistleblower was coming in and we’d have five minutes. The journalists would say, ‘They know you have our trust.’ It was a long process and when we got to editing, there was an option for the whistleblowers to decide at that point if they wanted to reveal their identity.

During editing, were you ever concerned about the explosive healthcare scandal you were dealing with and the legal ramifications?

We worked with a handful of lawyers who looked at things from all sides we were presenting from. We were following investigations that were made public way before the film, so we weren’t revealing anything new.