Lawrence Block, like many New Yorkers, seems to have felt his world shake and shift after 9/11.

	"ALL THE FLOWERS ARE DYING" By Lawrence Block William Morrow($24.95)

His last major publication, "Small Town," was a panoramic novel with a large cast from the city, all of whom were, in one way or another, reacting to the attack. Apparently Block, to use the jargon of the day, hasn't "moved on."

This new Matt Scudder crime novel, in both symbol and mood, continues the dark, ironic and elegiac aspects of "Small Town."

It does so on a much smaller scale and, I would add, takes the series back to the noir tone of the earlier novels when Scudder was a drunk, divorced, unlicensed private investigator going nowhere fast. Not a bad thing for nighthawk readers, who like their streets mean and their characters down and gritty.

Lately, Scudder's success (on the wagon, married, licensed and well off) has taken the edge off that fiction.

But thankfully, at least for his readers, 9/11 has put Scudder and New York out on the cutting edge again.

It is the absence of the Trade Center towers that sets the tone and theme here.

Characters tend to look out their windows and feel the absence of the towers as a sign of the emptiness in their lives or the uncertainties of the future. Or both.

Two single women are trying to fill their emptiness with new love affairs.

Monica, a dear friend of Matt's wife Elaine, is carrying on happily with a secretive married man.

Louise wants Matt, who she met at an AA meeting, to check out her similarly secretive new flame. She trusts him, but . . .

And these are only two of the people who are feeling a bit edgy as the novel begins. Joe Durkin, a cop Scudder knows from the old days, is on the verge of retiring and wants to become his partner, but Matt tells him that he's pretty much retired, too.

His old "office," Jimmy Armstrong's saloon, has been torn down, and he's no longer looking for clients. Elaine has retired as a call girl and now runs a small art gallery.

Old friends, like police artist Ray Galindez and hijacker Mick Ballou, have called it quits, the first replaced by a computer program, and the second just tired after a highly successful life of crime.

But one man is doing quite well. In alternating chapters, a cold, highly intelligent psychopath tells us how he murders three children in Virginia and then cleverly frames an innocent man for these crimes.

After attending the execution disguised as a psychologist, this criminal mastermind reveals the man's innocence and moves to New York City.

His story and Scudder's eventually come together, but not before the murders come closer and closer to Matt and Elaine.

It's a small world after all.

Scudder has to call on many of his old friends and acquaintances to help him find and stop this fellow.

Durkin, Ballou, and Galindez do their bits and T.J., the African-American street kid who helped Matt before, uses his newly acquired computer savvy to do some crucial research.

But ultimately it comes down to a cat-and-mouse game between Scudder and the man whose edge is a very sharp cutting blade. And Block plots the game flawlessly.

If there is a problem with this novel it is Block's portrait of the psychopath. He is so brilliant, so meticulous, so sadistic that he doesn't seem to belong to the same species as the other flawed and realistic characters in the story.

It is, however, his twisted genius that drives the action.

Like "Small Town," this novel has some graphic descriptions of violence and sex. And, even more than that book, it brings closer to home those contradictory feelings created by 9/11, that someone is out to get us and that violence and deaths are both random and senseless.

For Block it's still mourning in America.