When watching Cherry Jones transform herself into the meaty role of Sister Aloysius in John Patrick Shanley’s Pulitzer prize winning Doubt, one can’t help but have that rare, wonderful feeling that they’re the witness to something amazing.

Jones won a Tony for her chameleon-like performance and it’s clear she’s lost no steam reprising the role for the stage at the National Theater. And what a role it is. Sister Aloysius, the principal at a Catholic primary school, is a relic of sorts, preaching that teachers keep their distance from their students and adopt a strict approach to doctrine and discipline. It would be easy to see such a figure as hostile and imposing, and Jones is that at times, but is never without a wry, knowing wit that softens her image to us.

Aloysius has bigger problems than the tension between the old guard and the new – she has begun to suspect that the school’s well-liked priest and coach, Father Flynn (Chris McGarry) is taking advantage of the school’s lone black student. With only her instincts rather than hard evidence to guide her, Aloysius requires unwavering principles to face the nearly-insurmountable task of convincing the patriarchal church hierarchy of anything — let alone something this devastating. It is her steadfastness that makes us — and those around her — both relieved and alarmed that the fate of both the potential victim and the priest’s reputation rests in her hands.