Remember “Born Free,” the soaring fact-based 1966 movie about an orphaned lioness cub, Elsa, who her protectors, a couple named the Adamsons, successfully reintroduced into the wild?

Like so many things in life, the happy ending at the movies was in fact only the beginning of a great deal of suffering, tragedy and death.

PBS’ “Nature” documents what Paul Harvey might call “the rest of the story” in a Jan. 9 documentary, “Elsa’s Legacy: The Born Free Story,” which reminds us that raising lions as pets isn’t a particularly good idea — either for the big cats, or the people.

A coproduction of Brian Leith Prods., Thirteen and BBC in association with WNET.org, “Legacy” covers a great deal of ground in an hour and exposes sides of George and Joy Adamson the movie certainly didn’t, beginning with her obsessive devotion to Elsa — as if she were a child — and their terribly quarrelsome relationship.

As naturalist David Attenborough says in an extensive interview within the doc, “Born Free” is “a lovely and encouraging myth that we are at one with nature and that nothing awful ever happens. Death and destruction and pain and agony is not part of that myth. It happens to be part of the natural world.”

Moreover, the story doesn’t just include the problems that beset Elsa — who didn’t adjust to living among lions as easily as the movie’s song-accompanied conclusion would suggest — but also the lions that were featured in the movie itself, which was a huge international hit.

Why return to the story now? Because 2010 marks the 50th anniversary of the book, which — on the plus side — did a great deal to appreciate the public’s appreciation of wildlife and its ability to see animals as something more than just game.

In a way, “Born Free” was a feel-good precursor to the current wave of nature programming we’re enjoying right now, with productions like “Planet Earth” and “Life.” And while PBS’ contribution to the genre is sometimes easy to overlook, this installment of “Nature” reminds us that public TV can still hunt with that pack.