The frenemies at the center of the sleek psychological thriller "Always Shine" are actresses of the same age. That's where their similarities end — unless you count their mutual envy and the rules of female comportment that neither can escape. Quickly and venomously, a jaunt to Big Sur brings their professional jealousies to the surface. As the fog closes in, so too does the foreboding, expertly tuned to fraught dissonance by director Sophia Takal, who blends art-house flourishes with such horror conventions as the spotty cellphone reception that signals trouble.
It's how that trouble unfolds, in two brilliant performances, that gives the movie its under-the-skin sting. Anna (Mackenzie Davis, of "Halt and Catch Fire") and Beth Caitlin FitzGerald, ("Masters of Sex") embody a classic dualism. Call it Type A and Type B, assertive and submissive, bad girl and good.
The confrontational Anna is still waiting tables, though she's probably the more talented of the two. Beth, as conventionally feminine as her flowery luggage, is attentively accommodating. It's a quality that serves her well; she's making her living as an actor, albeit in slasher films that depend on "extensive nudity," as two unseen but vividly creepy producers emphasize during an audition.
In the sharp screenplay by Lawrence Michael Levine, who appears in a supporting role, performance and reality bleed into each other, finally spiraling out of control. While the foreshadowing proves more fascinating than the upshot, the two leads breathe jittery life into every sinister twist.
Running time: 1 hour, 27 minutes