Who’s afraid of the … wait, who is the Big Bad Wolf in this thriller?

Nearly every month, it seems, there’s an in-depth feature on the nightly news about the danger of sexual predators lurking in Internet chat rooms. The old conscience-kicking “It’s 8 o’clock; do you know where your children are?” is now “Do you know who your child is chatting with?”

It’s common now to read about some guy arranging to meet an underage chat partner, only to be trapped by a police sting. “Dateline” recently turned that around, tricking three junior high girls into giving personal information to a chat buddy – who turned out to be a police officer. He gently chided the girls, but the point was well-made: You can’t take anyone at face value when you’re online.

That’s the diabolical premise behind “Hard Candy,” the debut thriller by David Slade, now playing at the Tivoli Theatre. Only there are no TV cameras, no concerned cops and no safe ending ... just a 30-something photographer and the 14-year-old girl who is the target of his desire.

Hayley (Ellen Page) is the precocious girl, chatting under the red-flag nickname Thonggrrrrrl14. She starts an online acquaintance with Jeff (Patrick Wilson) and sparks fly. Soon Jeff has persuaded Hayley to meet him at a nearby coffee shop, and she eagerly agrees. Their online banter spills into real life with ease, and it’s not long until Hayley has agreed to let Jeff take her to his sprawling house in the hills to listen to some music – but the way they’re both acting, it’s clear they both have something else on their minds. He asks if she should let someone know where she’s going, but she nonchalantly dismisses the idea as they head out of town.

At Jeff’s house, Hayley dials up her Lolita-like charms to 11. Rummaging through Jeff’s kitchen, she finds a bottle of vodka and – with only token protest from Jeff – fixes them drinks. Soon she’s dancing on his sofa, doing a slow striptease, encouraging him to photograph her like the other young models he has hanging on his walls. Jeff, of course, is eager to comply. He grabs his camera and starts to work ... but things are out of focus. It’s not the camera; it’s him. He stumbles and passes out.

When he comes to, he finds himself bound to a chair, face to face with a young girl determined to mete out her own justice against a would-be pedophile. Little Red Riding Hood has captured the Big Bad Wolf, with the help of a dose of roofies in his screwdriver.

The rest of the movie plays out as a twisted version of their online interplay. But now Jeff is the prey, and Hayley verbally stalks him, forcing him to admit to his prurient behavior as she slowly prepares for her final act of vengeance.

Last month’s film, “Sophie Scholl: The Final Days,” also focused primarily on two characters in a battle of wits, set in a stark setting. But in that film, Scholl was the unquestionable moral center, an ill-fated but guileless heroine. There’s no such person in “Hard Candy.” The obvious villain is Jeff, who – through Hayley’s perspective, at least – is apparently a pedophile, preying on naïve young girls for his sexual gratification. He may even be responsible for the disappearance of one girl.

But set against Jeff’s charming predator is the obsessive Hayley. Nearly as soon as Jeff has come to, we understand just how extensive Hayley’s plotting was. Everything that transpired between them has been according to her plan, just to trap him. And now that she’s got him, her rage and single-mindedness border on psychosis. Hayley becomes truly terrifying, and it’s not difficult to start feeling sympathy for Jeff.

With the exception of only a few scenes, “Hard Candy” consists strictly of the interplay between Hayley and Jeff. It’s fortunate, then, that Slade had such incredible luck landing his two leads. Wilson has been stuck in forgettable fare (flops like “The Alamo” and “The Phantom of the Opera”) but finally gets a role that allows him to stretch a bit (despite being tied to a chair). But the real breakout star is Page, who is little-known outside of Canadian television. Ironically, she’ll almost certainly receive more publicity for her role in “X-Men: The Last Stand,” which also debuts this month. In that film, she plays Kitty Pryde, an ethereal girl who walks through walls like a ghost – quite a contrast to the unyielding Hayley.

When Jeff meets Hayley at the coffee shop, she’s innocently plowing through a slice of chocolate cake. Slade milks the scene for all its worth: tight shots of the fork sliding through the tender confection; the ingénue Hayley, lips coated with frosting; Jeff reaching down and dabbing it off with his finger – and licking his finger clean. “Hard Candy” definitely brings the sultry before it delves into the scary.

You can re-enact your own face-to-face rendezvous at Nadoz Café at the Coronado in Midtown. A cup of coffee and a slice of Chocolate Grand Marnier Cake should provide the necessary props. And, in case you’re dining solo, Nadoz is wired for WiFi. Just keep it legal, OK?