Conspiracy theories about the assassination of President Kennedy and one woman's involvement and paranoia should add up to a tense thriller. But very little works in Keith Reddin's Frame 312, a play in which the script and Next Stage's production fall short.

Cutting between 1963 and the 1990s, Redding imagines a secretary at Life magazine entrusted - and burdened with - the original Zapruder film, which in the play reveals multiple shooters. A snipped frame by the FBI presented the public with a far different story, the script says.

Redding takes that idea toward the conclusion that all of American history and, in microcosm, the woman's family have been tainted by corruption. He makes a weak case, though, in a script full of underdeveloped characters and lazy writing.

Lynette, the secretary at the play's heart, is played in youth and middle age by Laura Norman and Susan d'Autremont, and the twinning of this single low-key, competent woman makes one of the production's more interesting aspects.

In 1963, Lynette is polite and dutiful, learning from her avuncular editor (Jim Hunt) and socializing with her friend Margie (an overbearing character as played by Janelle Christie).

In the 1990s, she is newly widowed and visited on her birthday by two difficult children - the manically angry Stephanie (played by Jennifer Forsyth with an exhaustingly high-strung comedy) and the suburban, overreaching Tom (Josh Hartwell, subtle in a number of smaller roles).

Other than the references to the period, there is little that suggests the switch between decades. Mathew Kepler's costumes reflect 1983 far more than 1963 - where is the teased hair, the Jackie K. uniform that young professional women wore?

Reddin's script is the biggest obstacle, though. Characters say phrases like "the kitchen of our tasteful suburban ranch house" that writers write but people don't say. Lynette says the violence won't stop with Kennedy's assassination. "It's only the beginning," she says with a credulity-straining prescience. And the foreshadowing of one character's death comes out of the worst sob-sister movies.

Reddin seems to have been reaching for some linking themes in his play, but the stretch is far too much.

Frame 312

• Grade: C

• When and where: 7:30 p.m. Fridays and Saturdays, 2 p.m. Sundays, through April 7, Phoenix Theatre, 1124 Santa Fe Drive

• Cost: $18

• Information: 720-209-4105