Peter Gallagher played a pretty cool dad on “The O.C.” But even Sandy Cohen would be way out of his league in “The Gathering” (8 p.m., Saturday and Sunday, Lifetime), a spooky new weekend-long miniseries. Gallagher portrays Michael Foster, a seemingly happily married doctor whose wife, Ann (Kristin Lehman), vanishes one morning with no word of warning for Foster or their daughter, Zee (Jenna Boyd).

During his desperate search, he discovers his wife’s ties to a shadowy occult group. Actually, the clues arrive even before her departure. He has strange dreams and visions about incantations, circles of blood, mutilated crows and scenes of his daughter that would make Linda Blair’s blood curdle.

There’s plenty about “The Gathering” that borders on the absurd, but there’s lots to love, too. Set in the posh quarters of mega-rich Manhattan, the film evokes memories of “Rosemary’s Baby,” “The Omen” and other occult shockers about ambitious schemers who will do anything for earthly power.

Peter Fonda stars as a real estate tycoon out to change the world, or at least influence a New York mayoral race, using the instruments of an ancient and repressed witchcraft. Jamie-Lynn Sigler appears in her first TV work since “The Sopranos” as a teacher of comparative religion at Zee’s prep school who helps Foster understand his wife’s embrace of a shadowy world. When she offers her pedantic lectures on the paranormal, Sigler evokes memories of Meadow as a Columbia student showing off to Tony and Carmella.

This being a Lifetime miniseries, many of the horrors involve mothers and daughters, childbirth and other “women’s issues.” There’s nothing scarier than a coven in a maternity ward, or babies and sonograms switched at birth, or plaid-skirted preppy witches who appear to turn into crows. It may not all make sense, but horror buffs should go along for the wild adventure. And speaking of uneasy rides, this may be Fonda’s druggiest movie since “The Trip.”

¢ Leapin’ Lizards: It’s a show about snakes! “Dangerous Encounters with Brady Barr: Snake Bite” (9 p.m., Sunday, National Geographic) follows the noted herpetologist into a remote cave in Indonesia known as a “snake palace.” Not only does the intrepid Barr encounter a giant python, but he has to wade waist-deep in bat guano to make his introductions.

Tonight’s highlights

¢ MTV offers a glimpse at “Legally Blonde: The Musical” (12 p.m., MTV).

¢ Romantic celebrity gestures denied on “20 Acts of Love Gone Wrong” (4 p.m., E!).

¢ NASCAR racing (6:30 p.m., ABC).

¢ Adrian Paul stars in the 2007 shocker “Wraiths of Roanoke” (8 p.m., Sci Fi), about early Virginia settlers haunted and harrowed by the souls of dead Vikings. Yikes.

¢ Scheduled on “48 Hours Mystery” (9 p.m., CBS): A filmmaker and musician returns to New Orleans and find murder.

¢ Jon Bon Jovi hosts “Saturday Night Live” (10:30 p.m., NBC), featuring musical guests the Foo Fighters.

Sunday’s highlights

¢ Amy Finly (winner of “The Next Food Network Star”) hosts “The Gourmet Next Door” (12 p.m., Food).

¢ A game of charades proves revealing on “Desperate Housewives” (8 p.m., ABC).

¢ Rita urges Dexter to join a recovery program on “Dexter” (8 p.m., Showtime).

¢ Nora helps Justin on “Brothers & Sisters” (9 p.m., ABC).

¢ Larry bugs out on “Curb Your Enthusiasm” (9 p.m., HBO).