Blame it on "Twilight" or "True Blood," if you will, but the mania for all things macabre seems to have settled over the retail scene like a stylishly spooky fog. Jewelers took cues from Mother Nature's slithering, skittering critters, while designers such as Alexander McQueen and Gareth Pugh took a confident leap toward the dark side for their fall collections. To introduce a bit of subversive spice, look for tasteful renderings of skulls, spiders and bones ... oh, my.