Look for Shannen Doherty (“Beverly Hills, 90210”) to appear in the fantasy film “Witchslayer Gretl” (8 p.m., Syfy). It’s a follow-up of sorts to the Hansel and Gretl story, with Hansel returning to the forest 20 years after their dust-up with the wicked witch. Speaking of wicked spells, if she’s Gretl, why isn’t he Hansl? Just wondering.

Hansel’s out for revenge, but to his horror finds that his little sister — long thought dead — is now in cahoots with the evil witch.

This plot summary does not come close to capturing the staggeringly dreadful dialogue and performances you have to sit through to get to Doherty’s arrival. It’s as if the producers picked random women off the campuses (or beaches) of Southern California and asked them to try sorcery for a few days.

Nobody’s looking for quality here, but even the so- bad-they’re-hilarious movies have their limits. And this one is way over the line.

”Gretl” airs immediately following “Black Forest” (7 p.m., Syfy).

• On a similar note, Starz presents a five-episode marathon of “Spartacus: Vengeance” (8 p.m.). “Spartacus” is a higher-budget version of the over-the-top Syfy fantasies, but without basic cable censors getting in the way. In an earlier “Spartacus” review, I observed, “The violence is relentless, the nudity gratuitous and the dialogue a preposterous blend of fake Shakespeare and 21st- century obscenity. By my unscientific count, ‘Spartacus’ has the most throat slashings per hour of any show …”

Tonight’s other highlights

• VanCamp and Treat Williams star in the feel-good 2011 drama “Beyond the Blackboard” (7p.m., Hallmark).

• The darkly comic supernatural series “Being Human” (8 p.m., BBC America) returns for a fourth season.

• Meryl Streep and Anne Hathaway star in the 2006 fashion comedy “The Devil Wears Prada” (8 p.m., ABC).

• The Film Independent Spirit Awards (9p.m., IFC) celebrate quirkier film fare on the night before the big show.

• Mark Wahlberg, Minnie Driver, Mark Watson and Christina Perri appear on “The Graham Norton Show” (9 p.m., BBC America).