(Movie -- HBO, Sat. April 18, 8 p.m.) Filmed in Ontario, Canada by Specialty Films and Locomotive. Executive producers, Lucy Barzun Donnelly, Rachael Horovitz, Michael Sucsy; producer, David Coatsworth; director, Sucsy; writers, Sucsy, Patricia Rozema; story by Sucsy.

"Little Edie" Beale - Drew Barrymore
"Big Edie" Beale - Jessica Lange
Jacqueline Kennedy Onassis - Jeanne Tripplehorn
Phelan Beale - Ken Howard
Julius "Cap" Krug - Daniel Baldwin
George "Gould" Strong - Malcolm Gets
Albert Maysles - Arye Gross
David Maysles - Justin Louis

How could a ravishing young debutante and her life-of-every-party mother -- relatives of Jacqueline Kennedy Onassis, no less -- become crazy cat ladies, occupying a dilapidated 28-room East Hampton mansion? "Grey Gardens," an HBO movie inspired by the eponymous documentary shot in 1973, doesn't fully answer that question -- indeed, there's a rather sizable hole in the story -- but nevertheless has a fabulous time contemplating it, showcasing marvelous performances by Drew Barrymore and Jessica Lange. It's a must-see for those fascinated by the lore of the U.S.' modern Camelot, as well as another sure to be lavishly adorned movie for the pay channel.
Director-producer Michael Sucsy (who also co-wrote with Patricia Rozema) is such a devotee of the original documentary that he spends chunks of the movie grainily recreating scenes from it, while turning the filmmakers (Arye Gross, Justin Louis) into minor characters.

The film is strongest, though, when flashing back to portray mother and daughter before their descent, opening in the mid-1930s, when 18-year-old Little Edie (Barrymore) dreamt of being a starlet, and her vivacious mother, Big Edie (Lange), would entertain with elaborate song-and-dance numbers at parties.

"You're the mother of my children, not a showgirl," snaps her disapproving husband, Phelan (Ken Howard), who is soon out of the picture.

Events roll along innocuously enough, with Little Edie beginning a relationship with a high-powered married man (Daniel Baldwin), while Big Edie finds herself alone in that great big house. Yet when the tryst ends badly, the daughter takes refuge at home, even as the mother's resources wither. Even so, Big Edie refuses to leave Grey Gardens, despite exhausting her trust fund.

By the time the filmmakers encounter them in the early 1970s, they've settled into an oddly reclusive life, so much so that local authorities raid the place, which is overrun with cats and raccoons. It's not until then that Jackie O. (Jeanne Tripplehorn, looking the part, but without much else to do) takes an interest in their fate.

Beyond Big Edie's extraordinary attachment to the property, the movie doesn't fully convey who the enabler and the enabled were in this co-dependent existence. The two Edies are also, as one says, an "acquired taste," so their overly mannered speech and affectations -- coupled with the ravages of Bill Corso's uncomfortable-looking makeup, aging the stars 40 years -- require a bit of getting used to.

Barrymore and Lange nevertheless deliver vibrant, wonderfully theatrical turns, with Barrymore in particular seeming delighted to sink her teeth into a character this meaty after a blur of relatively forgettable romantic comedies. That's not to say "Grey Gardens" is without romance, but it's an unorthodox one -- in essence a love story between these two women who take refuge from the world in each other's company.

All told, it's an impeccably rendered piece, down to the smallest details -- the kind of lush, meticulous little parcel that relatively few outlets these days have the means or latitude to cultivate.

Camera, Mike Eley; production designer, Kalina Ivanov; editors, Alan Heim, Lee Percy; music, Rachel Portman; makeup, Bill Corso; casting, Ellen Parks. 104 MIN.