Sarah Ferguson is edgy.

She's working frantically to finish a three-part documentary investigation into child sexual abuse within the Catholic church while at the same time keeping a close eye on the dramatic events unfolding in Hong Kong.

In the New Year, Ferguson is moving to Beijing to head up the ABC's China bureau.

Being a foreign correspondent is a new direction in a career built on long-form investigative journalism and documentary making, but the rise of China is an irresistible story.

"China is the big story of the day and that's always going to drag me towards it as a journalist," Ferguson says.

"I don't understand a lot of the dynamics and I'd like to understand them better, and I'm sure if I'd like to understand it more a lot of other people would like to as well. It's no good sitting over coffee reading the Financial Times, I want to be there."

Sarah Ferguson interviewing Hillary Clinton for Four Corners in 2017.

Her toughest story yet

Difficult, confronting and harrowing stories are all in a day's work for Ferguson but the project that has consumed her for most of this year, Revelation, has tested her like never before.

Promising worldwide television firsts, the series (due to air next year) brings Ferguson face-to-face with church paedophiles who agreed to be interviewed and, with unprecedented access granted by the courts, for their trials to be filmed.

"It's extraordinarily intense," Ferguson says.

"I'm used to intense projects but this one has been more intense and more challenging than anything I have ever done and part of that is the nature of the material but also the production team has set the bar very high in terms of a television event."

And that's saying something.

This is the journalist who exposed shocking cruelty that forced the suspension of live cattle exports to Indonesia (A Bloody Business), secured exclusive interviews with the families of Katrina Dawson and Tori Johnson as part of a forensic investigation into the Sydney siege (The Siege part one and part two), convinced Kevin Rudd and Julia Gillard to dissect their bitter political feud in The Killing Season, and lived in a women's refuge to produce a confronting documentary on domestic violence, (Hitting Home).

Ferguson on the front line with police investigating a domestic violence incident in the documentary Hitting Home. ( ABC News: Hitting Home )

Ferguson can't reveal much publicly about Revelation yet as it's still in production, except to say the interviews with paedophile priests give an insight we've never had before.

"The experience of the few people who have seen the interviews is you can't take your eyes off them, but it also leaves a lot to think about afterwards," she says.

"This story about the Catholic church has been so much a part of our lives for a number of years that the moment of seeing the person themselves, the person who actually perpetrated these crimes, it is a revelation. It's dark but it’s compelling."

The blowback is bad and getting worse

Revelation promises to have an impact, as many of Ferguson's stories have.

But shining a light in the shadows inevitably upsets people — often powerful and nasty people — and the fallout over the years has taken its toll.

"The blowback is bad and getting worse — for individuals involved with you it's much more intense and the organised blowback against yourself, it's big league, it's hard and it's not for the faint-hearted," she says.

"After the cattle story some people wanted to quote, unquote 'wrap me in chains and drop me in the bottom of the harbour'.

"I think if we did the Four Corners rugby league sex scandal story now, I don't know if we would be able to protect the woman who spoke out in that story in the way we did then.

"You just have to hold the line and need really good management that will support you, which has always been the case for me at the ABC.

"I have never once felt that they didn't have my back."

Loading...

Driven by an intense desire to know what’s going on

To spend your professional life wading through murky waters, exposing unpalatable truths and skewering slippery interview subjects, you have to be gutsy, determined and steely.

Off camera though, Ferguson is warm, funny and engaging.

Her quick wit was on show in an entertaining 'Hard Chat' interview with comedian Tom Gleeson, which came about by accident.

Loading...

"I agreed to do it because I thought it was something else," she laughs.

"I didn't read the producer's email properly until the day before recording and then I realised what it was, and it was too late to pull out.

"I was sitting in the office where we are working on this series and I put my head up and said to the team "Oh my God, what have I done?"

"I had just finished the Four Corners story about the ABC, [investigating the relationship breakdown between sacked Managing Director Michelle Guthrie and Chairman Justin Milne], which was very sensitive, and we had to walk a very straight line between two competing stories.

"The defamation police had their sirens on, so I was worried about doing that interview at that time, but I did enjoy it.

"I love anything that makes me and other people laugh and I love having tables turned on me."

Sarah Ferguson at Cape Canaveral in 1994. ( Supplied: Sarah Ferguson )

That Ferguson was able to get both Milne and Guthrie to agree to participate in the Four Corners' program says a lot about her journalistic ability and the respect she's garnered over the years, according to friend and head of ABC Investigative Journalism John Lyons.

"Sarah has a strong commitment in her journalism to fairness. I've seen her do stories on people who are locked in conflict and yet they feel they are fairly represented by her," he says.

"Despite Justin Milne and Michelle Guthrie having had a bitter falling-out, both agreed to be interviewed by Sarah, as they trusted her, and both felt that their side of the story was accurately reported in what went to air.

"Her series The Killing Season highlighted the bitter political battle between Kevin Rudd and Julia Gillard, yet both were prepared to speak to Sarah.

"People on all sides of politics and across the spectrum trust Sarah, which is gold."

Lyons hired Ferguson when he was executive producer of the Sunday program. ( ABC News )

Lyons has known Ferguson since 2003, when, as the newly installed executive producer of Channel Nine's Sunday program, he recruited her from SBS where, as a video journalist, she'd learnt to shoot her own stories.

On assignment in South Dakota in the 1990s. ( Supplied: Sarah Ferguson )

"I could tell from her journalism that she was tenacious, had an extraordinary instinct for working out the heart of a story and had a particular skill at relating to people," he recalls.

"She proved to be brilliant — within the first year she had four Walkley nominations and went on to do some of the best stories Sunday put to air.

"Whether it's interviewing the prime minister or a child in outback Australia who has been through trauma, Sarah has a great gift for knowing what questions to ask and how to ask them.

"She combines the intellect of a good QC with a great emotional intelligence."

Ferguson has won multiple awards — four Walkley's, including the Gold Walkley for 'A Bloody Business', the Melbourne Press Club Gold Quill, five Logies, two Australian Academy of Cinema and Television Arts Awards (AACTA's) for best documentary, the George Munster Award for Independent Journalism and the Queensland Premier's Literary Award.

But that's not what drives her, rather it's a need to satisfy her intense curiosity.

"For me, in every moment, in every interaction I have, I want to know what's going on."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 12 minutes 28 seconds 12 m Sarah Ferguson discusses the making of the documentary Hitting Home and The Killing Season series about the Rudd/Gillard years.

Interrogating politicians from an early age

Ferguson was born in Nigeria in 1965 to adventurous parents, Iain and Marjorie Ferguson, who nurtured in her a quest for an interesting life.

"My parents had travelled a lot, so it was never questioned that you might choose to go to unusual places and do unusual things. It was normal to want to go and explore the world," she says.

When she was a toddler, the family, moved back to rural England and a small village in Essex.

Sarah Ferguson as a toddler in Nigeria. ( Supplied: Sarah Ferguson )

Ferguson's curiosity emerged early.

As a teenager she loved poetry and wrote a letter to her favourite poet, Philip Larkin, to ask him why his poems were so miserable, which led to several years of correspondence between them.

Her parents expected their children to know what was going on in the world and she grew up listening to BBC current affairs and surrounded by political debate.

Marjorie Ferguson was a local Tory party volunteer and one day, 13-year-old Sarah overheard a visiting political insider reveal that the local MP, and major player in the party, wanted to move to a safer seat.

When the MP turned up at Ferguson's school the next day, with local media in tow, the future journalist threw him a curly question.

"He thought he was having an easy afternoon patting us all on the head, but I put my hand up and asked are you committed to remaining in this constituency?"

"I knew he was looking for another one because I'd been eavesdropping, but I wasn't supposed to know that nor to ask about it and of course that became the story of the day."

Ferguson studied English Literature at university and started in journalism as an Arts reviewer before moving into documentaries — "I love the medium of television, I love what it can do," she says.

Tony Jones and Sarah Ferguson. ( Supplied: Sarah Ferguson )

Freelancing in Paris in 1992, she was hired by the ABC to work as a fixer on a story with Tony Jones, host of Q&A and then-foreign correspondent who she would later marry.

They've kept their personal and professional lives very separate over the years but are now working together on Revelation for the first time since they met.

"I have always had the view for a woman, in particular, that it's very important that your career is considered in its own light," says Ferguson.

"Tony has his job and I have my job and they don't need to cross-fertilise but the reason we brought him in on this project is that he is actually the best television writer I know of in Australia.

"He's a fantastic writer and filmmaker, and was so at Four Corners, and we needed that at this stage.

"We worked together when we first met but haven’t for years since.

"When you rang me we were just disagreeing about an interview grab in the opening of episode three, but otherwise it seems to be going ok! We try not to talk about the project after dinner, otherwise it's hard from morning to night."

Talk to your mother

While Ferguson has kept the lid firmly shut on her private life, last year she opened up, writing a deeply personal and moving book, On Mother, about love and grief following her mother's unexpected death.

She writes of the shock and anguish from the moment her brother, Anthony, rang her from the UK with the news as she travelled in a Sydney taxi, her investigation into the hospital's treatment of her mother, and concludes with a plea to readers to "call their mother" before it's too late.

"I don't know how to say it, so I'll just say it. Mother died." The bonds broke, snapping and uncoiling, like a thousand tiny ropes. I cried out. Tony tried to hold me, but I couldn't be held. Decades of restraint unravelled. On a broken line, Anthony tried to explain. "She was alone in hospital. We didn't know she was there." Not by herself. Not alone. No. I thrashed about in the back of the taxi, like something animal. (Extract from On Mother.)

Sarah Ferguson's mother, Marjorie. ( Supplied: Sarah Ferguson )

"It was publisher Louise Adler's idea and I said, 'but it's such an ordinary story.'

"She pressed me to do it and I accepted that uncomplicated love and sadness have their place and to express that was a valid thing to do.

"I'm glad I did it because I have this precious memory written down and doing the publicity, talking about it in places was fantastic, because it's such a rich event for everyone when it happens so you know you are touching people.

"And suddenly there I was in a community of people who understand this extreme thing in all its manifestations. That was just so special from start to finish and not something I would normally do."

We need to admit when we get it wrong

'On Mother' has special meaning for her but asking Ferguson which are the stories or programs she's most proud of it's like asking her to nominate her favourite child.

"It's probably all of them," she says.

"The Killing Season was a special team of highly skilled people led by Deb Masters working with exceptional material and then there's the people smuggling trilogy, which was difficult, very demanding and a rollicking investigation.

"All the best stories are about these intense collaborations, producers with steely analysis like Michael Doyle and Morag Ramsay, the exceptional finesse of Justin Stevens, the fresh gaze of Jeanavieve McGregor, on its goes - the crews and editors. So much talent.

"And of course, the inimitable Nial Fulton who made Hitting Home and is my creative partner in the current series and who is the most generous collaborator.

"It’s hard to pick out favourites from this great list because you give so much to every single one that I can’t pick one over the other.

"But if you know these people, you'll notice one thing above the skill, they are all very funny."

Ferguson with producer Deb Masters and cameraman Louie Eroglu during filming of The Killing Season. ( ABC News )

Calling out the contribution of the team around her is something Ferguson does frequently.

In half-a-dozen previous interviews about her projects, she's insisted on highlighting the work of key people from the executive producer to the sound recordist.

She's generous in sharing insights and advice with colleagues and younger journalists and is comfortable admitting she doesn't always get it right.

"I think it's not a good idea to think that people who do reasonably well in their careers do that by not making mistakes and by somehow being so brilliant that you can't aspire to that.

"We all make mistakes and I think it's better that less experienced journalists know that it's hard and you stumble, and you think about it because that's the key thing.

"You make a mistake, you stop and think about it, why did I do that?

"The other thing to consider is the vicissitudes of life and time.

"I've made some mistakes and sometimes that's to do with the intensity of the work we do.

"Those judgements, those big judgements actually get harder as you get older when there is more at stake.

"So, we need to talk and think deeply and admit when we get it wrong."

Ferguson interviewing Rosie Connellan and Thomas Zinn, the mother and the partner of Tori Johnson who was killed in the Lindt Cafe siege for a Four Corners program. ( ABC News: Louie Eroglu )

Stories that leave deep lines in your soul

In the era of the 24-hour news cycle, stories come and go with alarming speed and journalists are often under great pressure to move on quickly to the next big yarn.

Ferguson though is committed to maintaining contact and supporting those who have entrusted her with their story long after the program has gone to air.

"I've worked as hard after stories as I have in the making of them," she says.

"I have what I call my after-program service, where I always talk to people, sometimes for years afterwards, so that they don't feel that you've ripped their story from them, you've got something out of them and then you just move on. "Sometimes the cost of that is very high.

"My phone is always on and these are often complicated people and the aftermath is long.

"This kind of work leaves deep lines in your soul.

"I never used to talk about the impact because I had a very strong sense of duty toward the job and the people you are working with but that cumulative effect of both the hardship you are covering and the aftermath is significant.

"Looking back now I would advise my younger self to look after myself a bit better and not take all of that on."

Despite the toll it's taken at times, for Sarah Ferguson journalism is a calling.

And she hopes that in fulfilling her personal need to know what's going on that her work has been of broader public value.

"It is who I am and if they outlaw journalism, I'll be without a profession and without a lot of meaning.

"I love it and I hope it's been worthwhile for everyone else, but I do wish I'd got more sleep."