Families from 3,000 centuries -- or perhaps it's just three and feels like so many more -- populate Blackbird House, Hoffman's turgid collection of interwoven short stories set on a Cape Cod farm. Hoffman (''Practical Magic'') spins a phantasmagoria of color -- a white blackbird, red boots, apricot light, purple, pink, and white sweet peas, and a woman named Violet -- at the expense of plot, exposition, and dialogue. Somewhere in this rainbow, sons die, lovers leave, and people get married, but who cares? The characters are so unrefined and underwritten it would take a genealogist to untangle their relationships. That leaves you rooting for the return of a very hungry halibut, who makes a meal of a fisherman early in the book, to put the rest of these folks out of their (and your) misery.