This is definitely a comeback year for John Wells (“ER,” “China Beach”) following last season’s misstep, the muddled Irish stew “Trinity.”

First, Wells collaborates on the stellar “The West Wing.” Now he’s rolling out “Third Watch,” which debuts at 10 tonight on NBC before moving to its regular 8 p.m. Sunday time slot.

“Third Watch” is a natural progression from “ER,” as it follows the action back into the streets. It documents the exploits of the paramedics, beat cops and firefighters who work the “third watch” (3-11 p.m.) in a poor New York City neighborhood. This translates into plenty of fireworks, with burning buildings, traffic accidents and crime, both petty and major.

The predictable “Third Watch” doesn’t grab the viewer like “ER” did in its opener, which now seems like eons ago. There are too many characters to give each a proper history in a single episode.

Still, some did shine through. Skipp Sudduth (“Ronin”) is the wise veteran cop who gets saddled with a green partner (played by Coby Bell). Complicating matters is that the rookie is the son of his late partner, who got killed while on duty.

Michael Beach (“ER”) plays Doc, the battle-weary but compassionate paramedic. Kim Raver (“Trinity”) plays Kim, the paramedic, formerly married to a firefighter, who still gets off on the adrenaline rush of her job.

The thrills and pacing are built into the setting of “Third Watch.” The key for the series is how well its many characters get developed. In the first episode, too many were just stereotypes: the “gloryhound” cop, the fumbling rookie paramedic, the cocky firefighter. If these characters don’t get fleshed out, viewers will roll to other shows during the “third watch.”

Tonight’s other new show, at 9:30 on NBC, is “Stark Raving Mad,” the millionth variation on “The Odd Couple.” Fortunately, it’s one of the better ones.

“Odd Couple” clones depend on the strength of the two actors involved, and “Stark Raving Mad” has a talented pairing. The Felix in this case is Henry McNeely, a fastidious, germ freak book editor played by Neil Patrick Harris (“Doogie Howser, M.D.”). He’s been assigned to shepherd the Oscar in this scenario, horror writer Ian Stark (Tony Shalhoub, “Wings”), through the writer’s block that’s keeping Stark from starting his second novel.

The shtick here is that Ian loosens up Henry, while Henry makes Ian more responsible. But eventually viewers are going to tire of watching the latest thing Ian does to freak out Henry. A more talented supporting cast is needed, since the current one is negligible. The flamboyant Harriet Sansom Harris (“Frasier”) appears as Henry’s boss in the debut, and more of her would be a godsend.

The show’s creator, Steven Levitan, has put together a crack ensemble on “Just Shoot Me.” He needs more of that team spirit in “Stark Raving Mad,” or viewers will close the book on his new series too quickly.