The central conceit of Christopher Boal's new drama could have been lifted from a Farrelly brothers movie: A crazed sister kidnaps her brother's beloved shih tzu in the hopes of forcing him to confess to murdering her cats when they were children. But Boal approaches this somewhat unlikely situation with utter seriousness, plumbing it not for laughs but for psychological insights into the state of the modern American family. Surprisingly, it works. Director Eric Parness and his able cast oblige Boal with a taut and vigorous production, striking a note of frenzied agitation early on and carefully sustaining it for the remaining two hours. Setting his four characters through a brutal gantlet of reveals and confessions, Boal achieves that most archetypal of American character studies: the emotional unraveling of the seemingly well- adjusted individual. Patrick Melville as the successful, upwardly mobile brother is reduced by play's end to a desperate, self-loathing child, while Karen Sternberg as his sensitive but high-strung young wife must suddenly question the very foundations of their relationship. The breadth of Boal's insights are limited by the drama's obsessive focus on its own contrived scenario, but by play's end this hardly seems to matter. Long Day's Journey Into Night this is not, but it is a tight and effective psychological drama.