A lot of life happens in a bedroom – romance, arguments, laundry. In David Schulner’s play “An Infinite Ache,” a couple progress from youth to old age, all in the confines of that intimate space.

Interplayers Professional Resident Theatre’s earnest production features deep sadness, wit and two very fine performances by Todd Kehne, as Charles, and Yvonne Same, as Hope.

What really sets this play apart from a typical relationship drama is its form. Within minutes, we realize that this story won’t be told in a traditional way. In the beginning, Charles shows new acquaintance Hope his studio apartment. In one moment they are debating whether their evening was a date, and in the next they’ve been seeing each other for weeks.

When you’re dealing with infinity, you don’t need to explain every moment. If Charles and Hope’s life together is sand falling through an hourglass, then the playwright shows the audience only certain grains.

Even the set shifts, and the actors transform themselves and the scenery in front of the audience, an intriguing and theatrical convention.

The energy at the top of the show seems flat as the actors find their grooves, with Kehne trying a bit too hard to be awkward. And one of his long monologues is upstaged by Hope’s setting props that emerge from a “magical” suitcase.

But as soon as the floor starts moving, the play’s energy increases and builds in intensity until the poignant end. In one brilliantly written and executed sequence, the couple lies in bed, sleeping and waking, alternately turning on and off lights. Years seem to pass.

In one bit of dialogue during this sequence, Charles says he wants a dog. Hope says no. A dog barks. They both yell, “Shut up!” She says, “I’m sorry we had to get rid of the dog.” They sleep. The audience must be alert to notice these shifts.

These flawless transitions during this 90-minute, intermission-less play are a testament to Marianne McLaughlin’s direction, the technical crew and skilled actors.

While many of the issues the couple deal with – children, infidelity, poor hearing – are cliché and the dialogue in serious moments waxes overdramatic, the actors deliver it all with conviction.

Same’s monologue lamenting her guilt for causing the fatal fall of her baby mirrored a woman out of her mind with grief. And Kehne, who typically plays quirky characters, shows he has the chops to portray a serious role. His speech toward the end where he considers his life and his wife’s death and what she meant to him drew the audience into a tearful silence.

But “An Infinite Ache” is not a tragedy. Schulner peppers his script with clever humor that softens the blows, and audiences will find the familiar characters, theater magic and plot twist satisfying.