Thanks to its proliferation via television, the courtroom drama has a familiar format. We already know many of the obligatory lines — "Do you swear to tell the truth, the whole truth . . . "

But in 1934, when novelist Ayn Rand ("Atlas Shrugged") first wrote what was to become her only stage play, "Night of January 16th," it was unusual enough that backers feared people would stay away and that audiences would refuse to participate as members of the jury.

The courtroom drama is also straightjacketed into a rigid shape, speeches and testimony unfold in ordered sequence, and — aside from taking and leaving the witness stand and minor attorney posturing — there is little movement.

The drama unfolds through oral testimony, much like a series of ancient Greek messengers relaying events that have happened elsewhere.

The current production for The Actors' Group directed by Brad Powell stands up to both the play's age and the possible drag of courtroom conventions, and keeps us interested all the way to the final verdict. A good variety of short character performances make it work.

Elizabeth Wolfe heads up the large cast as a murder defendant charged with throwing her lover and former boss from a penthouse terrace. Danielle Vivarttas-Ahrnsbrak is the dead man's grieving young widow. Between the two women, it's a toss-up as to which shoots the most murderous glances around the courtroom.

Obviously, most of the testimony isn't "the whole truth," and arises instead from personal prejudice, mistaken judgment or downright brazen lies.

Robert Harrison is the doctor unable to examine a body that fell 50 stories to a cement sidewalk. Richard Goodman is the night watchman certain that one of the men catching the elevator was dead drunk. Non deMello is the private investigator whose eye-witness account came from a nightclub balcony after a few drinks.

Richard Valasek is the policeman distracted from hunting for clues by a dainty nightgown, and Karen Valasek is the housekeeper who moralizes on sin. Richard Aadland is the widow's wealthy father who would spare no cost in helping his daughter. Seth Lilley is the clerk who worshipped the dead man and David Albert is the hit man who worshipped the dead man's mistress.

The courtroom set works and the play's original three acts have been effectively collapsed into two.

In the end, the verdict is yours, and the play has two possible outcomes. Anyone familiar with Rand's philosophical themes will be led to a clear conclusion, however. Just follow the arrows that point away from conventional morality toward reason, productive achievement and personal happiness.

Joseph T. Rozmiarek has been reviewing Hawai'i theater since 1973.