Chatter, the smart and feisty second novel from Perrin Ireland, does. Chatter, that is. It skips and skitters along, slides sideways through the story of a marriage, through its strains and secrets and betrayals, and talks its way into a thorny conversation about how we live right now.

After 18 years, Sarah’s marriage to Michael is suddenly feeling shaky. It’s nothing she can put a finger on, maybe just the strain of so much time spent with the same person. While Michael has a grown daughter from a previous marriage, Sarah’s first husband didn’t want kids, and her childless state is one of her great regrets.

As the book opens, Sarah finds a phone message hidden in Michael’s shaving kit. Marked “urgent,” the call came from Camila Rodriguez, an unfamiliar name. Set against the faltering marriage — within a few pages we see Sarah and Michael in couples therapy, learn he’s secretive about his past, that a midlife crisis may be lurking on the doorstep of their lovely Boston life — this feels like predictable ground.

But you can relax. Perrin’s too savvy to throw us headlong into clich?. Early on, she telegraphs her promise that the scenes from this particular marriage will be anything but typical. Characters speak, well, the way we actually speak: with staccato cadences, in disjointed sentences, carelessly, sometimes caustically, with answers contained in code.

Here’s the first conversation we see between Sarah, a writer, and Michael, a charismatic business executive, as he arrives home late for dinner:

“In the soaps,” Sarah said, “the husbands never go to work, preferring to stay at home and discuss relationships.”

“I had to give a speech to the group from China,” Michael said.

“And the husbands in the soaps rent entire restaurants, with bands, to celebrate their anniversaries.”

“When I got back from the meeting, I had 243 e-mails.” He tossed his briefcase on the floor, his jacket on the chocolate-stained antique chair. “How’s Rachel?”

“I don’t understand why my friends have cancer and the leader of North Korea doesn’t.” Sarah rose from the sofa, jeans bunched at the knee, and he followed her into the kitchen, where the microwave flashed the wrong time and splashes of water surrounded the dog dish.

“Why don’t we get that thin pizza anymore?” he asked.

“There comes a point when you want a Dove Bar more than a roll in the hay.”

Camila Rodriguez turns out to be not a fling, but someone more treacherous — a daughter Michael never knew he had. Now in her 30s, she’s a gorgeous Latina journalist living in Miami, and her appearance leads directly to the secret of Michael’s years in the Peace Corps.

Camila wants to get to know her father. She’d also like very much to get rid of Sarah. But what she wants most of all is for her mother, Magdalena, the fiery young revolutionary with whom Michael had a fling, to reunite with her newfound father.

It’s a crazy plot, played out against the equally crazy days of post?September 11th paranoia. The noxious chatter of the media, radio talk of terrorist threats, news stories about domestic spying, TV screen crawls toting up the damage from the latest Al Qaeda bomb, provide a metronome of doom. Even as Michael seeks out Camila, spends time with her, and begins to side with her against Sarah, he refuses to talk about the past. Sarah digs for clues and finds herself looking at the end of her marriage.

What would become of her if Michael left her? She could have lunch with a different friend every day, but that was Chinese food — during her divorce, Sarah had calculated that it took five lunches with friends to equal one hour of emotional intimacy with a spouse. She wouldn’t have the energy to have as many lunches as it would take to stave off loneliness.

Ireland’s got a great ear, and Chatter has its funny moments. She gives Sarah a quirky sense of humor and leavens things with slice-of-life scenes we easily recognize. Here’s Sarah, suddenly scared to fly, being coached by a disinterested Michael.

Sunlight streamed through the window as the plane emerged from the clouds, and the ice in her plastic glass rattled.

A loud thump.

“Bringing up the wheels,” Michael said, not looking up from his magazine.

A crumpled paper cocktail napkin hopped across the floor. Another loud noise.

“Wing flaps,” Michael said, turning a page.

The young uniformed pilot or copilot walked quickly through the cabin, stopping periodically to peer through windows at the plane’s wing. He was chewing gum, and People magazine stuck out of his back pocket.

A stewardess tapped another stewardess on the elbow.

“He wants us to return to our seats.”

A woman across the aisle read a thick book because some people don’t have the imagination to picture a plane spiraling earthward through hoops of fire.

It’s a shame, then, when the lost-daughter plot spins out a bit too far. It thickens to the point that even Ireland, gifted though she is, can barely stir the resulting stew. A drug overdose, a suicide attempt, a long-ago murder, confessions, revelations, and a brief affair clog things up. We know these characters not so much from how they act but from how they react. The book’s all verbal razzle-dazzle, fine for a farce but far too frail to stand up to this much drama.

Throughout, Ireland has hinted at her wish for a happy ending, and she doesn’t let us down. She loves her characters too much. Instead, she turns Chatter into a post-apocalyptic fairy tale, where poof! — bad guys are suddenly vanquished, complications vanish, and good prevails.

Sure, there’s some loss, some sorrow and some sweet, sad goodbyes. But in the end it’s pretty clear, Sarah and Michael live happily ever after.