There is a two-word catchphrase that, while seated in The Audience, which opened Sunday night at the Gerald Schoenfeld Theatre, you may be tempted to blurt aloud in the darkness more than once. But, of course, you wouldn’t dare: This is Broadway, not Broad City, and you are in the presence of royalty. All such expressions of “Yaaass, Queen!” directed toward Dame Helen Mirren, returning here to the role of Elizabeth II, for which she won an Oscar in the 2006 film The Queen, will just have to remain on the inside. (Think of it as your first immersive step into British culture.)

The play also marks Mirren’s reunion with scribe Peter Morgan, who penned both that celebrated film and The Audience, which premiered on London’s West End in 2013 with Mirren in the role, also under the direction of Stephen Daldry. The play’s title refers to a long-standing weekly meeting held between the Queen and the Prime Minister in Buckingham Palace, and its action spans the Queen’s ascendance to the throne in 1952 through to the present. Assembled in non-chronological order, scenes jump from decade to decade, each inviting us to eavesdrop on a tête-à-tête between two of the world’s most powerful leaders in their time.

If you’re expecting a history lesson, well, you may find yourself getting a crash course (the crib sheet in the program will help), as these private conversations are inseparable from the public sphere. Undoubtedly, many of the play’s deeper subtleties hinge on our grasp of events unfolding outside the palace walls and the unique climate of international relations during a particular decade. To that end, Morgan does a fine job of anchoring the Queen as the world spins rapidly around her, generating a fixed point of view as events of various consequence and prime ministers of different temperaments come and go.

But Morgan’s play is foremost a fascinating character study, brought to life by Mirren’s stunning performance as the Queen. Mirren is one of the rare performers so vividly associated with a true-life figure, and watching her return to the role of Elizabeth II is something of a marvel. She disappears into the role like a second skin, seamlessly inhabiting different stages of the Queens’s rule—from the naiveté of her first audience (at age 25) with Winston Churchill to her unfazed aspect opposite David Cameron at the age of 88. (The astonishing costume changes and stately set are courtesy of designer Bob Crowley.)

The Queen is something different to each prime minister who steps into office: a mother figure and confessor to some, a friend or rival to others. But to us, as to her subjects, she remains constant. Much of what makes The Audience so compelling is feeling privy to the Queen’s inner life—being given the chance to recognize the personal character of someone whose outer persona is so ubiquitous. Monarchy—and politics—are, after all, theatre. And Morgan’s play offers a backstage pass to the longest running show in the world.