Two spinster sisters, their possibly schizophrenic maid, and a melancholy and philosophical mastiff spend their days dreaming of love and power in a ruinous old estate on the desolate, fog-enshrouded English moors (though, oddly, all of them seem to speak with American accents, even the dog). Jen Silverman’s “The Moors” is mysterious, menacing, and savagely funny postmodern mash-up of the Bronte Sisters and Samuel Beckett.