BOOK REVIEW : A Fall From Grace to L.A.’s Underside : THE BLACK ECHO, <i> by Michael Connelly,</i> Little, Brown, $19.95; 375 pages

Like a thief in the night, Hieronymus Bosch breaks into the home of the Dollmaker and shoots the craftsman in his bed. Deader than yesterday. The Dollmaker was unarmed. Hieronymus (rhymes with anonymous ) can’t get away with this outrage. Justice must be served.

The authorities demote Hieronymus and transfer him to Hollywood Homicide.

Hieronymus (Harry) Bosch, protagonist of Michael Connelly’s “The Black Echo,” is a sleuth who fell from grace with the LAPD. It didn’t matter that the Dollmaker was a sicko--a serial killer who painted his ladies before slaughter. Harry broke procedure and used excessive force, and in present-day Los Angeles exposing the law-enforcement family to unwanted media heat is a no-no. Like many fast-tracking Angelenos, Bosch finds himself detoured to the surface streets.

Harry is not a shooter by nature. He is a methodical, traditional, superstitious detective. When a unidentified body is found in a pipe near the Mulholland Dam, the first link in a long chain of coincidences develops. Twenty years earlier, Harry knew the dead man; they did a tour of duty as “tunnel rats” in Vietnam. Despite the spike mark in his arm, the late rat didn’t just die of a heroin overdose. He was murdered and dumped in a tunnel.

The Black Echo is the claustrophobic dank silence that tunnel rats experienced when ordered underground to flush and kill the hiding Viet Cong. The further his investigations take him, the further Harry is driven back to his personal abyss in Vietnam. For Harry the return of the echo is a subterranean nightmare of screaming sweats.

Harry links the dead vet with a “perfect crime”--a 10-month-old unsolved bank robbery. Legally, bank heists fall under the dominion of the Federal Bureau of Investigation. Harry has difficulty working with the FBI, but those are the rules. Adding to his problems are two Internal Affairs investigators who have him under surveillance. One more slip and Harry’s history.

The jurisdictional entanglement finds Bosch partnered with Special Agent E. D. Wish. The E stands for Eleanor. Both live without companion or even a pet. They have the vices of the self-sufficient: jazz, art and alcohol. They share little else. He chain-smokes; she chain-drinks bottled water. There’s an attraction on his part--and the professional impropriety attendant to it.

With Harry’s back story established, “The Black Echo” author (and Times’ crime reporter) Michael Connelly catapults his protagonists into the dark side and literal underbelly of Los Angeles: from Boytown to Little Saigon, and down into the 1,500-mile maze of storm drains and sewers below the City of Angels. In the five years since leaving the crime beat of South Florida’s Sun-Sentinel, Philadelphia-bred Connelly has clearly assimilated into the lifestyle and mind-set of Los Angeles. From 4 a.m. omelets at the Pantry to shortcuts up Woodrow Wilson, he knows his way around the city. “The Black Echo” could substitute as a local guide book for an uninvited lowlife house guest.

Connelly expertly combines the federal and local investigative procedurals with his journalist’s cold eye for accuracy (occasionally swamping the reader in an alphabet soup of official acronyms). Mention is given to inner workings of The Times, and the uneasy off-the-record currency of data swapping between the media and law enforcement.

Humor is dry and in short supply, but Connelly does have fun with character names: Ninety-Eight Pounds, Lewis and Clarke, Davy Crockett, a woman called Elvis, and Federic B. Isley (FBI). Harry is named after Hieronymus Bosch, a 15th-Century Dutch artist famed for his bizarre paintings of the underworld.

While Connelly is light-stroked with characters, he’s all muscle with plotting. At times “The Black Echo” whips the reader backward and forward with a vengeance. Connelly has crafted a ticking clock into the story, which takes place over an eight-day stretch in May. An eyewitness to the rat’s demise turns up murdered himself in a tunnel near the Hollywood Bowl. Wiretaps, CIA and INS sources indicate high crimes in high places. The unknown mastermind of the first “perfect” break-in is going for it again.

As an alternative to spending the forthcoming Memorial Day weekend standing in line for a thrill ride, you might want to put Sonny Rollins on the stereo, grab a cold one, and crack open “The Black Echo.” It’s a scary one.