“As a journalist, I’m used to asking difficult questions, but this was heavy-duty,” Pfeiffer says of the harrowing interviews with adults who were abused as children. “It was probably the most delicate interviewing we’ve ever had to do, because you’re asking people to describe traumas – sexual abuse.”

The film shows incredibly sensitive conversations Pfeiffer had with survivors of abuse, where she gently insists they be specific about what happened to them. “If we just said, ‘This person was molested’, it would have been such a generic, sanitised word that you would not have realised the horror of what went on. It could mean anything from a boy who had a priest slip his hands down his pants in the car when they went out for ice-cream to a boy who got raped. So we really had to push survivors within their limits to give us details, so we could understand if a crime happened and what kind.

“At times it felt like we became grief counsellors who weren’t trained,” Pfeiffer continues. “I worried about [the victims]. We were listening to people unearth something so traumatic, from decades ago. Sometimes we would finish a phone interview and then call back shortly afterwards and check they were OK, and to make sure they had someone to talk to.”

While she’s warm and friendly, Pfeiffer, as a highly efficient journalist herself, is intimidating to interview. When I ask about her life outside of work, she becomes more reserved. She says she met her husband as they both finished university at 21; they were married eight years later and she doesn’t have children. I mention that there’s barely any personal information about her online, a refreshing rarity in the age of social media. “I’m a private person,” she says, plainly.

Yet Pfeiffer lives and breathes her work. “It’s the most interesting job in the world,” she says. “It’s never boring, it’s like constantly being in school. It lets you ask questions that would be so inappropriate in any other setting. But it also gives you access to different worlds. Once, before I was on the Spotlight team, I had to go to a family court in the morning – usually a very tragic place. By lunchtime, I was invited by this very wealthy developer to lunch at the penthouse floor of his high-rise building.”

Aside from working full-time, Pfeiffer also speaks several languages and recently completed a Master’s degree in education from Boston University. In her spare time she teaches English as a second language and describes herself as “both a night owl and an early bird – I go to bed late and get up early”.

Pfeiffer was initially apprehensive about seeing her life on screen when the idea was put to her by Hollywood director Tom McCarthy. “I feared we would be embarrassed,” she says. “I thought that they would dramatise or exaggerate or stereotype what we did. Tom [McCarthy] recently said to me, ‘You seem like such a different person now from when I first met you’. Then he said, ‘But I realise that’s because at the beginning you were guarded.’ I guess I was.”

So how does she think she compares in real life to the person we see on screen? “It was strange to have a mirror turned on me,” she says. “When I was leaving the screening with my husband I said, ‘Do you think Rachel played me too intense and serious?’ He laughed and said, ‘You are exactly that intense and serious.’ It was surreal.

“Even the smallest mannerisms were accurate. My brother told me that sometimes when my hair falls in my eyes, I’ll just throw my head back – and Rachel McAdams does that in the film. I spent an hour on the phone to Rachel and we took a walk around Boston for several hours. Now I realise she was probably studying how I walked, talked, how I reacted.”

The Spotlight team’s lives became completely consumed by the case. But how do you begin to uncover such a vast scandal? “In newspapers we call [the process of investigating] ‘gathering string’,” Pfeiffer explains. “You look for a piece of string [evidence], and the string keeps getting longer. You just go with it, wherever it takes you, and then eventually you have a rope.

“With the Church sex abuse scandal, while the lawyers were trying to release the sealed files in court, we were trying to figure out everything we could – knocking on doors, making calls day and night,” Pfeiffer says. “We learned that there was a victim’s group – SNAP (Survivor’s Network of those Abused by Priests). We called every survivor. Every time we got a new piece of information, however seemingly insignificant, we followed it. It could be very demanding. As a reporter you don’t know if you’ll go home at 6pm or midnight.”

Following the publication of their first report about John Geoghan in 2002, Pfeiffer says the team anticipated repercussions. In a fervently religious town, accusations against the Church were blasphemous; during the investigation the Church even threatened to sue. Pfeiffer herself went to Catholic school (though her father was Protestant) and says she was nervous about how her own family would react to the report. “Yet, we got all this gratitude,” she says. “The phone didn’t stop ringing and it was mostly more survivors. Even now the movie is out [its US release was in November], we’re hearing from new survivors who finally want to speak, and old survivors we haven’t spoken to in a decade.”

It would have been easy for the dark nature of the stories to take their toll on Pfeiffer, but she says it made her even more driven. “One of the hardest things about this project was the amount of time we spent talking to people, usually adult men, who were talented,v articulate and smart – but were still devastated by something that had happened when they were children. I love having the privilege and ability to walk into someone’s life for a few hours, and have this powerful story come out.”

The stories have stayed with Pfeiffer. “Sexual abuse is the kind of thing I’m not sure you ever recover from,” she says. “It’s even worse if it was by a priest – someone in a position of trust and power. When you see people so wrecked decades later it makes you very angry and that anger becomes a motivator to keep reporting.”

The team continued to report on the scandal for a further 18 months before moving on to new projects. In 2008, Pfeiffer moved into broadcast journalism, becoming a radio show host at NPR (National Public Radio). Since 2014 she has been back at The Boston Globe investigating the conduct of non-profit companies and charitable foundations.

Yet the force of her work on Spotlight over a decade ago is still very much a part of her life. The film and its rallying cry for the power of traditional, local reporting, she says, is incredibly important to her. Yet, the story’s impact on the survivors will be the team’s most pertinent legacy. “I have victims who stay in touch with me today,” she says. “One in particular I get calls or emails from several times per week. I think this movie has been a healing thing for many of them. They felt so alone and they were afraid to come forward at first. Now they feel empowered.”

Meet journalist Sacha Pfeiffer, the woman who took down the church and inspired the movie Spotlight