“I’m glad you’re back to being sisters again,” Alan (John Turturro) says to his daughter Dana (Jenny Slate) towards the end of Gillian Robespierre’s “Landline,” unaware that he largely – and inadvertently – bridged the differences between Dana and her younger sis Ally (Abby Quinn), which spanned age and disposition. The two both find themselves hiding away in the family’s summer house, separately in need of some time away from their lives in the city, where the restless Ally is ready to start a life away from her parents, already sneaking out at night to party in warehouses and leaving post-it notes on her pillow to explain away her whereabouts to her mother Pat (Edie Falco), while Dana is suffocating under the weight of an approaching wedding to her genial fiancé Ben (Jay Duplass), whose uncomplicated affections won her over as someone who shies from drama but she worries won’t challenge her as the years wear on. Their anxieties are only heightened by Ally’s discovery of a trove of poems written by Alan suggesting an affair, unsettling as much for the idea that he would ever cheat on Pat as it is that something that always felt so rock solid could be upended as they prepare to make decisions on which to build the rest of their lives.

As with her debut “Obvious Child,” Robespierre’s great gift is to envision complicated relationships with the clarity and sharpness with which she lands the many comic punchlines in “Landline.” Set in the simpler times of the 1990s, the film pokes a small bit of fun at dot matrix printers and retrieving your phone messages from a pay phone on the street, but seems to delight more in piercing the self-delusions of its characters who have all burrowed into routines that no longer serve them well. It’s why after you’re introduced to the Jacobs clan – full of fight, to be sure, but in the way you only can be with loved ones, you can understand why Dana’s increasingly susceptible to the entreaties of Nate (Finn Wittrock), a matinee idol handsome friend from college who none-too-subtly mentions he’d like a “Jewish-Italian wife to watch ‘Mad About You’ with,” even as she and Ben continue to shower together as they have for the past five years, or Ally turns to more and more dangerous fixes to take her mind off things.

Robespierre resists ever sitting in judgment of the decisions they make, but has the rare ability to show how they do make up their minds with a light touch, working from a script of steadily accumulating power that she co-wrote with Elisabeth Holm with strong attention to emotional detail. The film boasts tremendous performances all around, with Slate once again serving as the ideal leading lady for Robespierre in her talent for being incredibly vulnerable in one scene and a comic wrecking ball the next. She is matched beat for beat by Quinn, a wry, winning presence who eludes garnering easy sympathy as Ally, instead showing a grit that you can’t help but admire. In giving nearly as much consideration to Alan and Pat, Robespierre gets even more ambitious with the ideas about intergenerational influence that created some of the most resonant scenes in “Obvious Child” and with old pros such as Turturro and Falco on hand, “Landline” make family dysfunction look elegant. While nothing may come easy for the Jacobs, you can’t say the same for Robespierre, who turns the intense pressure her characters feel into another gem.

“Landline” was picked up for distribution by Amazon. It will play the Sundance Film Festival once more on January 27th at 8:30 am at the Egyptian Theatre.