A neighbour hides a sinister secret in this astonishing new play at Tarragon Theatre

But “The Neighbours” strikes at the core of what horror ought to be: an outward manifestation of our deepest, darkest insecurities, delivered in a way that raises the hair on your forearms and twists your stomach inside out.

The kind of horror in Billon’s play is more unsettling than any ghouls, ghosts or supernatural forces. It traffics in the horror of hindsight — the kind that forces us to question who we are, what we stand for and who we believe ourselves to be.

Throughout the play, Simon (Tony Nappo) repeatedly asserts to his wife, Denise (Ordena Stephens-Thompson), that if he were living in Nazi Germany during the Second World War, he would be confident that he’d help save the Jews.

But Denise isn’t so certain. Toward the end of the play, when she confronts Simon on that subject one final time, there’s a sense of fear — and yes, horror — in her eyes.

“I hope we would be. But I don’t know for sure. Maybe,” she says, her voice faltering. “Surely it was easier to look the other way, pretend what was happening wasn’t really happening …”

What makes “The Neighbours” so riveting and terrifying is that Billon forces us to sit in Denise’s uncertainty. Almost in real time, we watch as she and her husband pick themselves apart, unravelling everything that they thought to be true.

Billon, however, doesn’t rely on grand, unexpected twists to propel his story forward — the kind that continually pulls the rug out from under audiences, offering more shock than substance.

The play’s biggest reveal, in fact, comes early on, as Denise and Simon’s quaint lives are upended one morning by the sound of sirens on their cul-de-sac, when they learn that their next-door neighbour was behind a horrific crime that stretched over 12 years.

“The Neighbours,” which takes place seven months after that discovery, focuses on the couple as they come to terms with their possible complicity. How could they have not known what was happening in the house right beside them? Or did they perhaps have an inkling of what was going on, but simply chose to conveniently ignore all the signs? 

Denise and Simon are foils for each other. She, a nurse at a local hospital, is almost always poised, speaking with clarity, each word intentional. Simon, meanwhile, is brasher and more unfiltered, with random thoughts and occasional profanity spilling out.

The play is told almost entirely through direct address, with Denise and Simon speaking candidly to the audience. 

Billon applies this storytelling device intelligently. It breaks down the barriers between the characters and the audience, fostering a sense of intimacy, as if we’re in Denise and Simon’s home with them. But it also sets up a dilemma that Billon forces the viewer to reckon with. How much can we trust Denise and Simon? And more fundamentally, how much can they even trust themselves? 

Stephens-Thompson and Nappo are exceptional as the married couple, especially as we watch them confront that latter question and head down a painful path of no return.

Director Matt White’s physical production favours surrealism over strict realism. Kelly Wolf’s set features a miniature model of a house, broken into pieces and suspended over the stage. On the floor is a map of Denise and Simon’s neighbourhood, including the houses that line their cul-de-sac. 

But the most intriguing aspect of Billon’s play, and White’s production of it, is the inclusion of a third character: Au Yeung Wei (Richard Tse), another one of Denise and Simon’s neighbours. He’s on stage for the entire show — reading a book in an armchair and sipping tea from his cup — but remains a shadowy, mysterious figure throughout. 

The only things we know about him are what Denise and Simon choose to share: that he’s quiet, reserved, and enjoys long walks as well as tending to his Japanese zen garden. 

One could argue that his character is underwritten, or even unnecessary. But his presence on stage is somehow inexplicably haunting and sets up a curious dichotomy on stage for the audience to consider: we seemingly know everything about Denise and Simon, but know next to nothing about Au Yeung Wei.

But does simply knowing someone — or thinking we know someone — enough for us to place our complete trust in them?