Irish theatre fans will likely have heard that in 2018, history was made in the Peacock Theatre in Dublin. In October, Rathmines Road, written by Deirdre Kinehan and presented by Fishamble Theatre Company hit the stage.

It was a dynamic and powerful drama, examining identity, trauma, and cultural and personal responsibility around sexual assault. What also made the play a landmark was the performance of Rebecca Root, who became the first trans actor to play a trans character in professional Irish theatre.

Root, now appearing in Jacque Audiard’s western The Sisters Brothers, played Dairne, a trans woman who returns home to visit an old friend, Sandra – who hasn’t seen Dairne since her transition. As the two catch up, their experiences of feeling ostracised – as well as the pressures of gender and the nature of identity – come to the fore. So too does Sandra’s experience with sexual assault, and the shame that surrounded that experience.

Root, who had her big break in the BBC sitcom Boy Meets Girl – one of the first ever UK television shows to feature a trans person in a lead role – not only gave an incredible performance in Rathmines Road, but was a part of two post-play panel discussions. As Hot Press film critic, I participated in one, discussing gender and identity alongside trans theatre-maker Robyn McQuaid-O’Dwyer, and TENI (Transgender Equality Network Ireland) chair Sara R. Phillips.

In The Sisters Brothers – based on Patrick deWitt’s novel – a local brothel owner called Mayfield feels like a familiar Old West type: a powerful, intimidating man who owns a popular watering hole. But in Jacques Audiard’s adaptation, Mayfield is played by Rebecca Root, giving her scenes an intriguing and refreshing quality. In a film (and indeed genre) dominated by men, she is one of the few women who speaks – and the only one with power.

Questions have been asked if Mayfield is the first-ever trans character in a western – but Root didn’t approach the character as trans.

“I played her as cis, actually,” Root told Vanity Fair. It seems like a progressive choice, as few trans actors are given the opportunity to play cis characters – a frustrating form of discrimination when we acknowledge how many cis actors play trans roles, severely limiting opportunities for trans actors, as well as trans representation onscreen.

But while Root played Mayfield as cis, writer-director Audiard seemed to be playing with ambiguity. “They never really identified Mayfield as being trans,” the actress said. “I kind of wanted to pin them down a little bit, but they were sketchy on it. In the end I thought, I’m just going to trust them… They never said it’s important that this woman is trans. They wanted that ambiguity.”

The ambiguity is interesting. While having a trans or gender non-binary character in a western might alter our perceptions, Audiard doesn’t push the point. Had he and the producers openly stated that a trans actress was playing a cis character in a film with an A-list cast, it might have been transformative. Is having a moment of ambiguity in a film more important than making a bold choice that could have had a wider impact?

What is not at all ambiguous is Root’s dynamic and compelling presence onscreen, as she transforms a potentially cliched character into one of the film’s highlights.