Let's get one thing straight right off the top - there was nothing missing from "The Thorn Birds."

And the only reason for "The Thorn Birds: The Missing Years" is to try and wring a few more dollars from Colleen McCullough's novel.Executive producer David Wol-per and his minions should be ashamed.

Wolper's original miniseries was a grand adaptation of McCul-lough's novel, covering decades in the life of Meggie McCleary O'Neill and Father Ralph DeBric-cas-sart - the ill-fated lovers whose lives were interwoven amid heartbreak and tragedy.

The miniseries started where the book began and ended where it ended - with the death of Father Ralph - spanning the years 1920-62.

And it was stunningly successful. First airing in March 1983, "The Thorn Birds" is still the second-highest rated miniseries of all time, trailing only "Roots." And it has done boffo business in two more runs on the network as well as two runs in syndication.

Asked why he made "The Missing Years," Wolper told critics about how incredibly successful - and profitable - the original series had been.

"As you remember, in the original `Thorn Birds' we skipped over about 15 to 20 years of the story," Wolper maintained.

But that's not exactly true. The notion that there are "Missing Years" in "The Thorn Birds" is inaccurate.

Yes, the original miniseries skipped over some of the events in the book - but almost nothing in this new two-part movie bears any resemblance to anything that was in the book.

What has happened is that Wol-per and script writer David Stevens have taken McCullough's beloved characters and built a mundane - sometimes ridiculous - story around them that not only pales in comparison to the original but often directly contradicts events in both the book and the first miniseries.

And "The Missing Years" revolves in large part around a custody battle - a plot that has been told and retold in countless TV movies and episodic series. And often told a lot better than this.

It's not so much that Richard Chamberlain is the only member of the original cast to return to "The Missing Years." Or that he's way too old to be playing the part of Father Ralph.

It's not that Rachel Ward and Bryan Brown aren't around for the sequel. (Meggie is now played by Amanda Donahoe, and Simon West-a-way takes over the role of Luke.) Or even that Jean Simmons no longer adds her considerable presence as Meggie's mother.

The problem here is that Wolper and Co. told the whole story the first time around, and what they're foisting on us as "The Missing Years" is a pale, distorted reflection of the characters McCullough created.

Stevens' script is just an piece of dreck.

The producers went to great trouble and expense to re-create the sheep station Drogheda as it appeared in the original mini-series. ("The Thorn Birds" was shot in California; "The Missing Years" traveled down under to Australia to film the follow-up.)

But it might have been nice if they'd put one-tenth the effort into re-creating something that approximated the original story.

Just a few of the many, many things wrong with "The Missing Years" are:

- Father Ralph, who never did an unselfish thing in his life, is suddenly a veritable saint - risking his own life to save Jews in Rome during World War II.

- In perhaps the miniseries' most ludicrous moment, Rome is being bombed by the Allies and the hidden Jews are panicking. To calm them, Father Ralph leads these Jews in a recitation of the Lord's Prayer.

- Throughout a large chunk of "The Missing Years," we're repeatedly told that the Australian sheep station Drogheda is experiencing a terrible drought. And yet, things look fairly green and the rose garden is in full bloom.

- In both the book and the original series, Meggie's mother was rather grim and taciturn, keeping her pain to herself and not interfering in Meggie's life. In "The Missing Years," she's suddenly chatty and gregarious - and she's constantly telling Meggie what to do.

- In both the book and the original miniseries, both the fact that Meggie's oldest brother was illegitimate and the fact that Meggie's son, Dane, was fathered by Father Ralph are closely guarded secrets known only to a few. In "The Missing Years," just about everyone seems to know.

And while Meggie is stunned by her mother's revelation that she knows the truth in the latter part of "The Thorn Birds," in "The Missing Years" mom makes it clear she knows the truth - and Meggie's not surprised in the least.

- In both the book and the original miniseries, the distant, damaged relationship between Meggie and her mother isn't repaired until the 1960s. In "The Missing Years," they're getting along famously in the 1940s.

- In both the book and the original miniseries, Meggie doesn't repair her relationship with her daughter, Justine, until the 1960s. In "The Missing Years," the rift is repaired in 1943.

- In "The Missing Years," Father Ralph offers to leave the Catholic Church for Meggie - which directly contradicts his behavior in both the book and the original miniseries and undermines the whole basis of "The Thorn Birds."

Remember, the "The Thorn Birds" was based on the fact that Ralph would never give up his role as a priest for the woman he loved.

One has to wonder whether many of those involved in "The Missing Years" were even familiar with "The Thorn Birds." When someone suggested that perhaps the story could continue with Meggie's children, Dane and Justine, "Missing Years" director Kevin James Dobson piped up and said, "That's a good idea."

Actually, it's not. Dane drowned in "The Thorn Birds."

Stunningly, Wolper agreed with Dobson. He did, however, add, "I think we've done `The Thorn Birds' now. . . . I think this is the end of `The Thorn Birds.' "

We can only hope.