IN THE 19th CENTURY, when the novels of Charles Dickens were appearing in England in serial form, a few chapters at a time, American readers waited eagerly at the docks for the ship bringing over the latest installment. It is not easy to imagine such a thing happening today. Yet my local bookseller reports that, in the final week of each of the last four or five months, her customers were stopping by frequently to ask if the latest volume of Michael McDowell's Blackwater had been delivered.

Blackwater is a serial novel, published by Avon in six paperback volumes -- each more or less complete in itself, but really only part of a larger, richer whole -- at the rate of one each month from January to June. McDowell is the author of three horror novels (The Amulet, Cold Moon Over Babylon, and The Elementals) and two very dark novels of 19th-century America (Gilded Needles and Katie). All were published as paperback originals and all were very successful.

McDowell's strengths are many. His prose is rich, allusive, and often intricate, yet so smoothly polished that it never distracts from the table. He has a terrific ability to get at the dark side of human nature and to delineate the psychological depths of eccentric and bizarre characters. His usual mode is to adopt an omniscent view and gradually reveal all to us as his characters disport themselves. He is in many ways a 19th-century novelist with a 20-th century sensibility. He is a wonderful writer.

And he is the perfect writer to carry off a project like this. Blackwater is an immense family chronicle -- telling the stories of the Caskey family and a strange woman named Elinor Dammert in Perdido, Alabama, from 1919 up to the present -- and it is also a chilling and memorable horror novel, filled with dreadful threats, monstrous deaths, and even more monstrous births. As a family chronicle, it provides a view of the larger patterns that escape us in real life, and it draws us into the essence of the Caskey family and makes us want to know -- from page to page, and from volume to volume -- what is going to become of them. As a horror novel, it is dark and disturbing, strange enough to read wide-eyed and frightening enough to shiver at afterward.

It begins with a flood of the Perdido River and the inexplicable appearance in town of Elinor Dammert, a woman with no visible origins but with hair the color of the Perdido's red clay banks. Elinor at once wins the hearts of some of the Caskey clan, Perdido's first family. One of those she wins is Oscar, son of Mary-Love, the family's matriarch. Mary-Love instantly senses in Elinor a threat to her position and, just possibly, a threat to all that is good and holy and right in the way the Caskeys live. In her strong and wily way, Mary-Love opposes Elinor at every turn. But if Mary-Love has a will of iron, Elinor Dammert has a will as patient and relentless as the flowing current of the Perdido itself. The battle -- all the more bitter for being mostly silent -- is joined, and it will persist even past the eventual death of Mary-Love, still several volumes away.

There are literally dozens of characters here, and every single one of them -- young, or old, black or white, good or bad or a little of each -- has the unmistakable air of a fully realized individual. There are scenes of the ordinary life of the Caskeys that are charged with excitement; some of the family gatherings have more tension than we've seen since the Forsytes last got together. And there are scenes in the private life of Elinor, and later of her daughters, that will make your blood run cold and that would positively freeze the blood of the Caskeys, if only they knew what the reader grows to learn.

Among the major attractions of Blackwater is its structure as a serial novel, and Avon deserves praise for undertaking it. The appeal is rather like that of a good TV mini-series, with many of the same advantages. The story and characters have the scope in which to grow. The reader need not make a large initial investment; rather the writer must compel the reader to return for more by the sheer power of his storytelling. Perhaps most important of all, the serial form, like the miniseries, gives us time . . . to catch our breath, to absorb what we have read, to think bout it, to feel the passage of years and the changes in characters: to participate, as it were, in the narrative process.

The recommended intake of Blackwater is one volume per month, but with all six now available, you probably won't be able to wait. Try to read it slowly. Make it last.