"Borderline" is just that. Borderline. Representing little more than a pay check for a slew of actors and production people, "Borderline" is a B-flick from the get go. Gershon is at the center as a prison psychiatrist whose ex-husband is murdered after securing custody of the divorced couple's two daughters. Gershon, who just happens to be dating an investigator on the case, is suspect and spends the run time trying to convince everyone, including the audience, of her innocence. With a threadbare plot, an uneven portrayal by Gershon, and ordinariness in all aspects of the film, there's little reason to spend time with "Borderline" unless you happen to surf it on cable and are in the mood for a convoluted mystery flick. (C-)