Picture this: you’re riding the subway in New York City when you spot a handbag that must have been left behind on one of the seats. Most passengers would ignore the bag, a few might heed the warnings given by the MTA and call the authorities, but Francis, the protagonist in Neil Jordan’s new psychological thriller “Greta,” is guided by her conscious to return the dull green purse to its owner. This is only the first in a long string of bad decisions.

The owner of the handbag that Francis (a charmingly naive Chloe Grace Moritz) meets is named Greta (Isabelle Huppert at her best). She’s a kind, older French woman who lives in a quaint home tucked away in Brooklyn. She’s recently widowed and her daughter, the light of her life, is studying in Paris at a conservatory. The only way Greta combats the loneliness is to play Liszt’s aching ballad “Liebestraum” on her tall upright piano and invite sweet young girls over for tea. It’s a cute act.

Things start to go off the rails when Francis discovers a cabinet full of identical green handbags, each handily equipped with Greta’s ID card and designed to lure other helpful girls to Greta’s home. After being given the cold shoulder by Francis, Greta, not one to be tossed away like yesterday’s bagel, becomes relentless in pursuing her friendship with Francis. As the game of cat and mouse intensifies, the wackiness of the story only grows.

To be perfectly honest, “Greta” is not a good movie. Its intriguing premise is quickly and easily wasted by Jordan and the decisions that the characters make throughout the film are laughable. At the end of the movie, it’s easier and more enjoyable to cheer for Greta than for any of the people we’re supposed to like, but that’s part of what makes it so fun.

Isabelle Huppert dives headfirst into this role, using the endearing old lady schtick as merely a warm-up to her theatrical portrayal of the psychopathic stalker later on. She oscillates between silly and enraged with ease and purpose as she works to manipulate and gaslight poor Francis. One moment Greta’s dancing on tiptoes around her prey, pricking them with sharp syringes filled with anesthetic, the next she’s flipping tables at five-star restaurants. No strategy is out-of-bounds for this stalker.

Chloe Grace Moretz also does well in her role as Francis. Even though her character isn’t given much else to do besides looking constantly terrified, she commits to the role more than anyone would expect her to. One of the best parts of the film is watching her make the worst decisions as Francis and know that somehow things have to still turn out alright.

The plot moves along well but gets tangled up towards the end, and some convenient coincidences and clever planning bring important characters together at crucial moments. Through all of the escapades, Greta remains unflappable. She’s just a sick old lady who really wants friends, and while her methods aren’t the best (or legal) we can all sympathize a little with her motives.

So, maybe “Greta” isn’t going to pick up the next Oscar, but there’s something to be said for a campy thriller, especially in a season when any entertainment will suffice to distract from the cold. If you’re looking for a way to fill your Saturday afternoon, “Greta” might be a wonderfully silly distraction.