Lust. Love. Lies. Sex. Those timeless elements drive the action in "Closer," playwright Patrick Marber’s dark but beautifully detailed look at modern relationships.

With Jim Aina, Michelle Hurtubise, Hannah Schauer Galli and the actor known as Q playing Marber’s vividly drawn characters, All the World’s a Stage’s production is rewarding must-see theater for adults and for pre-adults mature enough to be involved in adult relationships.

Dan (Q), a journalist who wants to be a novelist, meets Alice (Hurtubise) after she has been hit by a car. He takes her to the hospital. She convinces him to take the rest of the day off. A relationship follows.

A year later, Dan’s book has been picked up by a publisher, and he’s trying for quick sex with Anna (Schauer Galli), the photographer who is shooting his publicity photos. Alice catches them, has a heart-to-heart with Anna and ends up as one of the subjects in Anna’s photographic studies of "unhappy people."

Dan and Alice stay together but Dan is obsessed with Anna. Fooling around in an Internet chat room, Dan pretends to be Anna and then arranges for a man who meets "Anna" in the chat room to go to a place where Dan knows she is likely to be. The man, Larry (Aina), goes to the meeting place, sees a woman and asks whether she is Anna. It is Anna — and she is stunned by his expectations.

However, despite the circumstances of that first meeting, Anna falls in love with him. From there on things get complicated.

Are there times when it is better to lie to your lover? Are there times when it is better to leave some questions unasked? Is it ever really "just sex"? Marber’s exploration of these questions and others makes "Closer" a relationship litmus test for couples willing to take it — and thought-provoking theater for all.

The production is also a fascinating platform for four marvelous actors. Watch the emotions flicker over Aina’s face in scenes where Larry is blindsided by circumstances; watch Schauer Galli respond to Aina or Hurtubise or Q in others; watch Q in the scenes where Dan chases his dreams and the scene in which Dan pays the piper. The subtle nuances of the actors’ performances make "Closer" a wondrous thing.

Hurtubise is equally impressive. She does an incredible job in a scene where Larry finds Alice working in a strip club, switching convincingly between several personas as a "private dancer" who will play whatever role the customer wants to pay for. The full meaning of the scene becomes clear much later.

The one problem with the production is that Hurtubise is so adorable as Alice in those early scenes that Dan’s initial pursuit of Anna seems unconscionable in every possible way. But there are times when lust conquers all.

Another set of issues gradually emerges to stir one’s thoughts. How permanent is the thing that first attracted you to someone — is it likely to fade or fall? And what happens if you no longer have the quality that initially made you attractive to them?