Among the countless perversities and mysteries of TV, the slighting of ''Scrubs" has been notable. Why hasn't this sly sitcom been an Emmy magnet during its four seasons? How come viewers haven't made it a Nielsen hit, or at least a cult sensation that gets fetish pieces in Entertainment Weekly? Why does NBC shuffle it around the schedule every year like a dung-puck, withholding season five until a gap happened to open up in the Tuesday lineup?
Yes, this is another tribute to the underappreciated hospital sitcom, which returns tonight with two episodes at 9 on Channel 7. ''Scrubs" deserves it. There is something giddily inventive about producer Bill Lawrence's laugh-track-free show, which crams its weekly 22 minutes with visual, verbal, and aural comedy, not to mention a bit of drama. With its density of material, it doesn't waste a second of time upon the electronic stage. ''Scrubs" operates like a tight, ''Simpsons"-esque animated series, and ''Arrested Development" probably wouldn't be so rich and hyperactive if ''Scrubs" hadn't paved the way. At a time when too many TV writers cruise on automatic pilot, there is nothing lazy or clone-like about ''Scrubs."
Surrealism is the show's most obvious distinction. ''Scrubs" is a hard-core TV product, in that so much of it is manufactured in post-production, unlike the more theatrical live-audience format of, say, ''Will & Grace." ''Scrubs" takes the fantasy sequences that David E. Kelley pioneered on ''Ally McBeal" and runs with them, constantly popping curious images into the action. It's as if the ego and the id of lead character J.D. Dorian (Zach Braff) were loosed upon us, as his every weird thought becomes literal and materializes onscreen. When inappropriate things pop into our brains, we edit them out. But ''Scrubs" edits those same things in, creating a fantasia of desires and fears and, J.D. being J.D., delusions of grandeur.
The production tricks do dazzle, but they aren't there to cover up a dearth of character. ''Scrubs" is built on one of TV's tightest ensembles, as the actors bounce off one another with the comfort and expertise of the casts of ''Friends" and ''Seinfeld." Their characters exploit each others' weaknesses, but affectionately, at times so affectionately it's downright moving. You believe these guys have been cooped up together for years within the same white hospital halls.
The likable Braff is at the center, but Donald Faison is essential as his flippant best friend, Turk. Together, they are juvenile and yet somehow touching in their quirky insecurities. And then Turk wouldn't be Turk without the constant vigilance of Carla, who is played with comic ferocity by Judy Reyes. Sarah Chalke is so endearing as the flaky Elliot, whose on-again off-again relationship with J.D. is currently off again.
The cast is filled out with broad characters who seem to represent aspects of J.D.'s coming of age. The nameless janitor (Neil Flynn) appears around every corner like an angel or a devil, to puncture J.D.'s pride; Dr. Cox (John C. McGinley) is the raging mentor with amazing windpipes; and Dr. Kelso (Ken Jenkins) is a walking lesson in how easy it is for a caregiver to lose his heart. All of these players are sharp, having created characters who are so original and unstereotypical they probably couldn't fit in on any other TV show. Try saying that about anyone on ''According to Jim."
The new season starts a little slowly tonight, as the writers and actors pick up where they left off last year. Most returning shows need to get back in shape after a hiatus, before they can sprint forward again. But even in its slack moments, ''Scrubs" is superior. It speaks in a comic language that reeks of Generation X, with many ironic allusions to the pop culture of the 1970s and '80s, but it also has great universal appeal. When a fantasy sequence set to ''Kung Fu Fighting" pops up tonight, everyone will get a kick.
Matthew Gilbert can be reached at email@example.com.