ON THE SURFACE, Blue Door is a simple production: two actors, one set, 90 minutes about one man's dark night of the soul, no intermission. The protagonist, a mathematician named Lewis (Victor Mack), begins the play in the manner of a casual storyteller, mixing humor and despair as he tells the story of his wife leaving him, his father's death, and the loneliness that has led to his current insomnia.

And then the dead ancestors start arriving.

The force behind these ghost relatives is actor Seth Rue, the perfect counterpart to Mack's tempered, unadorned performance. Rue is a whirlwind, moving between characters, dialects, and time periods with staggering agility.

Between the stories of his ancestors, Lewis' dead brother (Rue) challenges him to look at his own life, to admit the lasting effects of slavery on their family and the ways Lewis has tried to hide from this history. As Lewis' scholarly work on the mutability of time begins to fuse with these unstuck-in-time relatives, the once simple-seeming story opens up even further, taking on racism in academia, the line between success and assimilation, and West African myths.

Tanya Banfield's expansive script presents a balancing act of threads, histories, and ideas that director Bobby Bermea and team field with impressive grace. There are few moments that feel like they're struggling with the play's scope; the production largely manages to ride some unknown line between sparse and elaborate, complimenting both the simplicity of the show's structure and the bulk of the script.

It's not until Blue Door is over that you can wrap your mind around how much Mack and Rue are cramming into their time on stage. Together the two do the work of a full cast, introducing us to over 20 characters over the course of the performance. The ease of their complex interplay makes it possible to watch the play and not lose the threads, to maintain the illusion that at its core it's a simple production.

Blue Door
Profile Theatre at Artists Repertory Theatre, 1515 SW Morrison, Wed-Sat 7:30, Sun 2 pm, through April 24, $20-27, profiletheatre.org