If it bleeds, it leads

A homicide detective takes the bus to a crime scene. It sounds like a joke, and “The Wire” finds at least one laugh in actor Dominic West’s hangdog expression as Detective Jimmy McNulty rides public transportation.

HBO’s superb, sprawling crime drama affirms that, however absurd, the civic crises underlying the situation are no laughing matter. For its fifth and final season, “The Wire” (airing at 9 p.m. Sundays beginning Jan. 6) still offers a seemingly omniscient vision of American life through the prism of Baltimore crime and punishment. No dysfunctional institution is too big, and no petty annoyance or act of unexpected decency is too small to escape the attention of creator David Simon and the rest of “The Wire’s” stalwart crew.

For 13 years a reporter for the Baltimore Sun, Simon returns to the newspaper for “The Wire’s” final season, folding journalism into the show’s omnibus of city problems. The depiction of police departments and the inner-city drug trade in “The Wire” has always been so persuasive that you feel like you’re on a ride-along with a veteran patrolman. The show also proves so skilled in finding humor and conflicts at middle schools, city hall and labor unions that “The Wire” could find gripping drama at libraries or animal-control departments, if only it were continuing.

The final season finds the police and the press as passengers in essentially the same leaky boat. Theoretically motivated to protect the public, both professions suffer not only from human frailty but exhausted resources. The dedicated officers of “The Wire’s” Major Crimes Unit struggle with lack of overtime and automobiles (hence the bus trip), while we see the Sun suffer a round of cutbacks comparable to those faced by Atlanta newspapers in recent years. Management offers the mantra “We have to do more with less,” an uninspiring motto that may define most aspects of modern American life. (Even “The Wire” must make do with 10 episodes for its final season, instead of its usual dozen.)

When the brass shuts down the Major Crimes Unit, crippling an investigation into usurping drug lord Marlo Stanfield (Jamie Hector), McNulty concocts an audacious scheme to turn the tide. The show’s de facto central character, McNulty stayed on the margins of the fourth season, putting aside major crimes for domestic bliss and simpler ambitions. In the fifth season, his boat-rocking ways and his personal demons return with a vengeance, suggesting that being a good person and fighting the good fight may be incompatible.

The newsroom storyline proves reminiscent of the dockworkers subplot in “The Wire’s” second season. Though always engrossing and sharply observed, the Sun scenes feel less fresh and more familiar than “The Wire’s” crackling portrayal of cops and criminals. The skeptical city editor (Clark Johnson) seems a little too saintly, and the ambitious reporter (actor/filmmaker Tom McCarthy) a little too reckless with the truth. Still, the newspaper environment feels as accurate as any documentary while expanding the show’s already massive scope and moral indignation. Police brass and newspaper management alike seem indifferent to crimes against impoverished black people. I’ve seen about half of the episodes of “The Wire’s” final season, and the show not only lives up to its skyscraping high standard, it’s turning increasingly suspenseful as characters embark on collision courses. Simon even seems intent on checking in with virtually all of the show’s (surviving) supporting roles, from inner-city folk hero Omar Little (Michael K. Williams) to Port Authority Officer Beadie Russell (Gone Baby Gone’s Amy Ryan) to the fourth season’s besieged young students.

The show’s fatalistic attitude about urban life may sound like grim fare, but the paradox of “The Wire” has always been that a show so disheartening can be so exhilarating. It’s as addictive as any street narcotic partly because the actors give such relaxed yet intense performances, speaking such funny, pungent lines of dialogue while capturing the realities of why cities rise and fall. And even amid vicious rivalries or domestic tragedies, a sense of camaraderie comes through, as if the wire of the title connects the whole hapless human race.