JUST WHEN IT SEEMED SAFE TO RETURN TO PRIME TIME...

Byline: Renee Graham Boston Globe

What, sweeps again?!

It seems like we just extricated our bleary eyes from the last monthlong television orgy of miniseries, specials, broadcast premieres of theatrical films and surprise guests on regular series. That was in February, and the networks already have started their engines for this, the final sweeps period of the 1995-96 season.

Among May sweeps offerings are a May 1 retrospective of 20 years of Barbara Walters' celebrity specials, the killer calamari of Peter Benchley's ``The Beast'' and one more delightful trip down the Yellow Brick Road.

Like every sweeps month, which also occurs in November, this is the period local stations use to set their advertising rates. But what makes the May sweeps different is it marks the finale of the TV season. All the first-run episodes denied viewers while they were deluged with repeats will be carted out in the coming weeks. (That's right, ``ER'' fans; Thursday night was the start of a good thing - no more reruns for a while.) And, most important, this is the month of cliffhangers, when series' producers and writers dangle tantalizing story lines in front of our faces - only to continue them next season.

``This is basically the last, great push of the TV season,'' said one network executive. ``Whatever tricks we have up our sleeves, this is the time to shake them out. What we do here is also important because the cliffhangers can set the stage for a quick start for shows in the upcoming fall season.''

End-of-season cliffhangers can even boost shows that were shaky throughout the season. After getting murdered in the ratings all year, ``Murder One,'' the acclaimed ABC drama, won its time slot Tuesday with its finale. Its ratings were 50 percent higher than the program's season-to-date average.

Networks begin advertising their programs months in advance. NBC first advertised its miniseries, ``The Beast,'' back in February during the second night of its miniseries, ``Gulliver's Travels.'' A month later, CBS was running ads for one of its big May sweeps entries, the miniseries ``A Season in Purgatory.''

NBC, winner of the last sweeps period and 11 out of the past dozen May sweeps, is hoping for an early lead tonight with its adaptation of ``The Beast,'' based on ``Jaws'' author Benchley's best seller. Starring William Petersen, the four-hour miniseries concerns a big squid wreaking havoc on a small seaside town.

Both CBS and ABC will offer miniseries as well. CBS, which placed second in February, offers ``A Season in Purgatory'' May 5 and 7 starring Patrick Dempsey, Brain Dennehy and Blair Brown in Dominick Dunne's tale of rich people doing very naughty things. On May 19 and 21, CBS airs ``Every Knee Shall Bow: The Siege at Ruby Ridge,'' about the tragic confrontation between the FBI and an anti-government white supremacist in Idaho; it stars Randy Quaid, Laura Dern and Diane Ladd.

ABC has television's latest take of the poetic westerns of Larry McMurtry May 12 and 13 with ``Dead Man's Walk,'' starring David Arquette.

Sweeps are also the preferred time for the broadcast premieres of theatrical releases. Among those scheduled on NBC: ``The Fugitive,'' starring Harrison Ford, May 5; the Tom Cruise-Jack Nicholson military drama, ``A Few Good Men,'' May 12.