“Nobody does something for nothing,” Maxine states flatly from her hospital bed. That’s the golden rule for the characters of Lucas Hnath’s “Death Tax,” a dense psychological thriller centered around an elderly woman’s ability to manipulate her caretakers and family.Directed by Ken Rus Schmoll, “Death Tax” premiered Thursday at Actors Theatre of Louisville’s 36th Humana Festival of New American Plays, which runs through April 1. Maxine (Judith Roberts) is dying in a nursing home. She’s clever but suspicious of everyone. She believes her estranged (and broke) daughter (Danielle Skraastad) is bribing nurse Tina (Quincy Tyler Bernstine) to hasten her demise and create a more favorable tax situation for her sizable estate. Maxine strikes a bargain with the bewildered Tina, who sees an opportunity to benefit from her patient’s paranoia. When caught, Tina cuts her boss Todd (Paul Niebanck) in on Maxine’s plan, but they soon find they have different motives for staying involved.Hnath structures his story in five scenes, presented without break in the intimate Victor Jory Theatre, to which scenic designer Philip Witcomb has added a menacing drop ceiling and unforgiving fluorescent lights to create a feeling of pervasive, clinical dread.Hnath’s style relies heavily on the unrelenting rhythms and textures created by extensive repetition in a series of lengthy monologues. There’s a clear David Mamet influence at work. It's compelling, but with Hnath’s drastic affinity for the extended monologue, the effect is overpowering. Dramatically, the strongest scenes are those with more dialogue between actors, though the playwright’s reliance on single voices emphasizes how the characters don't listen to one another until they hear what they want to hear. Still, the play feels long for its story as a result.It takes strong acting to carry Hnath’s dense writing, and luckily Schmoll’s cast is first-rate. Roberts commands every scene she’s in from the moment she steps into her hospital bed—imperious, charismatic and enigmatic to the end. Bernstine shines as the scrappy nurse who finds herself clinging to an ever-shifting moral ground, and her scenes with nebbish Niebanck crackle with unchecked desperation and need.Skraastad’s powerful performance as Maxine’s broke, desperate daughter is both moving and subtly suspicious. Is she genuinely wounded or is her appeal to the nurse a ploy to win her mother’s heart—and cash?And Is Maxine delusional or merely vindictive? Is Todd wrong to challenge Tina’s motives? It’s hard to say, and that’s a problem for a psychological thriller, where the story develops not through action but through character. “Death Tax” lacks a clear hero, and the absence of a character who reflects more than his or her own truth keeps the audience from truly understanding the actions of anyone but perhaps Maxine, whose tenacity is to be admired, if not exactly liked. Key plot points are left unresolved, too, making for an unsatisfying end to a compelling story.