What if having even several hundred million dollars still didn’t make you happy? Not a concern, for most of us, but that’s the situation facing Harry and Aleeza (Zach Braff and Ari Graynor) an unhappy, 30-something couple, in “Trust,” Paul Weitz’s latest dark comedy.

The off-Broadway world premiere, in a limited run at Second Stage, is frank and often funny, though ultimately hollow.

Braff, best-known as the hapless young doctor J.D. in the TV series “Scrubs,” is well-cast as a discontented, seemingly charming, self-deprecating man.

Harry’s dot-com multimillions have unexpectedly led to him and his wife feeling paralyzed with ennui and trapped in meaningless lives.

Such wealth and boredom are unthinkable to the other two people in this play, which also features Tony Award-winner Sutton Foster as dominatrix Prudence and Bobby Cannavale as Morton, her unemployed, fast-talking, thuggish boyfriend.

In one of the funnier scenes in the play, Harry encounters Prudence when he steps outside his comfort zone in a desperate attempt to feel excitement again.

Their meeting leads to unexpected interactions among the two couples, as power battles are waged, distrust runs rampant, and people struggle for meaning and control in their lives.

Crisply directed by Peter DuBois, fast-paced scenes unfold on Alexander Dodge’s bright set. Surprising plot turns and witty or brittle exchanges occur in almost every scene, but the overall impression is like a cartoonish flip-book, with some developments too convenient to be credible.

Weitz has provided plenty of sharp-edged zingers, but much of the behavior of these not terribly likable people simply lacks credibility.

Trust cast: Bobby Cannavale, Sutton Foster, Zach Braff, Ari Graynor

Prudence, the most sympathetic character thanks to Foster’s subtle performance, is a repressed, emotionally damaged woman who shields herself from the world with a tough persona.

Trouble erupts when Morton “reaches out” to his unsuspecting girlfriend’s client, and not in a good way.

Cannavale is surprisingly funny as Morton, repeatedly switching from being overconfident and volatile into a self-despairing heap of failure.

Graynor does her best to project some personality, though she spends the first act mostly wallowing in bed, as a near-suicidal former artist who can no longer paint because being wealthy makes her so unhappy.

Aleeza’s bewildering eventual career choice feels contrived, like much of the play.

These dissatisfied characters are all lost in different ways, but Weitz’s too-pat ending doesn’t land them any place that’s truly satisfying. One wishes the attractive, talented cast had been given more solid material.

Jennifer Farrar is a theater critic for the Associated Press