Throughout her film and television career, comic actress Aubrey Plaza has proven her distinct knack for portraying nerdy introverts. But as the titular character in “Ingrid Goes West,” a favorite at the Sundance Film Festival last January that earned writer/director Matt Spicer and co-writer David Branson Smith the Waldo Salt Screenwriting Award, Plaza has taken her comedic prowess to another level by proving she can do just about anything.

In what is by far her most challenging, three-dimensional role to date, Plaza plays the troubled Ingrid Thorburn, a mentally unstable social media-alcoholic who, shortly after her mother’s untimely death, becomes obsessed with Venice and California-based social media influencer Taylor Sloane (a perfectly cast Elizabeth Olsen), a beautiful and bubbly style icon whose wildly popular Instagram feed is chock-full of selfies and pictures of avocado toast.

With her mother’s inheritance money and an obsession-fueled “shoot first, ask questions later” plan to befriend Taylor in tow, Ingrid drives from her suburban Pennsylvania hometown all the way to Venice, where she is quickly able to rent an apartment from landlord Dan (a scene-stealing O’Shea Jackson Jr.), an aspiring screenwriter who still loves Batman with childlike zeal. Dan isn’t oblivious to the red flags Ingrid presents, but he’s genuinely intrigued with this new tenant with disarming candor and a big bag of cash.

After finding out where Taylor lives with her husband, a fedora-wearing starving artist type appropriately named Ezra (a terrific Wyatt Miller), Ingrid manages to kidnap Taylor’s dog with disturbing ease so as to orchestrate the opportunity to meet Taylor and Ezra and ingratiate herself into their lives. To Ingrid’s delight, Taylor takes an initial shining to her new bestie. But when Taylor’s suspicious playboy brother (Billy Magnussen) arrives from out of town to surprise his sister with a visit, Ingrid’s precarious web of lies begins to unravel in ways both hilarious and alarming.

Dark comedy is perhaps the riskiest of movie genres, because to produce it effectively requires a near perfect balance of humor and perturbed subject matter, two storytelling elements that couldn’t be any less congruent. But in his feature debut, Spicer confidently navigates this tightrope with remarkable consistency. Time and again, “Ingrid” delivers delicious sequences that make you laugh out loud and cringe in discomfort all at once. And while the film’s third act does lose its sense of humor as well as its previously tight grip on the chaos a little bit, it never loses its cutting sense of purpose.

Spicer also helped his cause by making virtually perfect casting choices here, the charge of course being led by the energy of Plaza in a powerhouse performance that I predict will earn her a Golden Globe nod for Best Actress in a Comedy next year. As expected, Plaza brings her signature wry wit to the table, but she also imbues with humanity — peppered with dashes of psychosis — which is truly fascinating to watch on screen. Plaza succeeds in presenting Ingrid’s faults in a way the audience can understand, and maybe even sympathize with, but, like the script itself, Plaza never gives in to the urge to let Ingrid off the hook.

With a talented cast elevating a smart script, “Ingrid Goes West” provides crucial social commentary on the dangers of confusing popularity with self-worth, and how easily the lines can be blurred in the age of social media, in which “likes” are king. While the film’s final scene feels a touch easy, by that point, “Ingrid” (which is rated R) has already succeeded in holding a mirror up to society and leaving us with an uncomfortable truth: there’s a little bit of Ingrid Thorburn in all of us.