AllMovie

Gladys Brockwell, one of Fox Studios' impressive stable of "vamp" actresses, played a dual role in The Moral Law. While Isobel de Costa (Brockwell) lives in her wealthy father's luxurious Florida mansion, her half-sister Anita (also Brockwell), the product of her father's youthful indiscretion with a "woman of the world," lives in her mother's Buenos Aires gambling emporium. On his deathbed, the guilt-wracked De Costa begs Isobel to seek out Anita and share half of her inheritance. Meanwhile, the hot-blooded Anita murders Umberto (Joseph Singleton), her live-in lover. Thus it is that, upon arriving in Argentina, Isabel is arrested for Anita's crime, while Anita heads to Florida, where she impersonates Isabel and installs herself in the family mansion. Fortunately for Isabel, Anita is tripped up by her own wanton nature, and the original "status quo" is restored.