While occasionally unpleasant, the film never crosses the line from bearably chilling to unbearably gruesome, keeping its characters credible and its events explicable.

Although Scalene slows to a drip in places, strong performances and a Hitchcock-trained eye build unnerving tension into its depiction of the intimate stress of caring for an invalid and the ways people might or might not crack under it.

Carefully crafted and impressively thesped, particularly by Margo Martindale, Zack Parker's ambitious, self-styled thriller channels a wide spectrum of high-concept classics, from "Rashomon" to "Memento." But the resolution of its conflicting truths proves so bizarre and idiotically off-the-wall that it mitigates all that precedes it.

More concerned with the novelty of its three-act, "three-perspective" structure than with how that structure actually functions (hint: poorly), Scalene epitomizes the pitfalls of the Memento-copping trend, its strained conceptual ingenuity an exercise in aid of nothing.