“Don’t touch anything on the subway.” That should be a warning posted in all New York City tourist brochures. Recent NYC transplant Frances didn’t get the memo. She not only picks up a “lost” handbag but also wants to personally return it to the rightful owner – despite the counseling of her streetwise roommate. Oscar-winning director Neil Jordan (The Crying Game) co-wrote Greta with Ray Wright, and they blend in many elements…not the least of which is making friends with someone you shouldn’t.

Chloë Grace Moretz plays Frances as the good-hearted Boston-raised girl who is almost too innocent to believe, given the day and age we are in. When Frances returns the purse, she is greeted warmly and appreciatively by a kindly Greta (Isabelle Huppert). The two bond over their individual loneliness: Greta says her daughter lives abroad, and Frances’ mother passed away about a year ago. It’s easy to see how a friendship forms through a substitute mother-daughter gap-filling.

An accidental discovery by Frances sends her out the door, intent on cutting ties with Greta. What Frances soon learns is that Greta is a crafty psychopath of the highest order. It’s at this point where filmmaker Jordan kicks in the twisted, dark humor and serves us a cheap-thrills ride via a full-blown stalker movie.

Greta is truly deranged and once Ms. Huppert cuts loose, we see how much fun she’s having. She even plays a piano teacher, which is kind of funny since she was also the piano teacher in The Piano Teacher (2001). She becomes my first and favorite Liszt-loving psychopath.

There are stylistic and story elements reminiscent of movies like Fatal Attraction and Single White Female, and Jordan’s camera angles and lighting combine with Javier Navarrete’s score to dish up some B-movie type comically dark moments. Maika Monroe (It Follows) is terrific as Frances’ roommate. She’s the direct type who tells Frances that “this city will eat you alive,” but is also extremely supportive and protective (and good at yoga).

Stephen Rea and Colm Feore appear in limited roles, but the fun you have here is directly related to how you buy into the Greta vs Frances web. It’s rare to see an onscreen female predator, but neither Mr. Jordan nor Ms. Huppert round off any edges. We are reminded that being nice doesn’t always pay off, but having friends certainly does. There is some creepy evil fun to be had, as well as a key life lesson: never trust a woman with too many purses.