Based on the short story "Hateship, Friendship, Courtship, Loveship, Marriage" by Alice Munro, the title-abbreviated "Hateship Loveship" is modest in size but considerable in impact. A slice of life impossible to guess its trajectory, the film deftly casts the invaluable Kristen Wiig (2013's "The Secret Life of Walter Mitty") in an entirely straight, achingly vulnerable role unlike any she has ever attempted. As the dutiful, somewhat withdrawn Johanna Parry, a housekeeper and caretaker who arrives to maintain order in the lives of Mr. McCauley (Nick Nolte) and teenage granddaughter Sabitha (Hailee Steinfeld), Wiig carries the picture with quiet, resolute dignity. Had they taken a more cynical approach to the tale, director Liza Johnson (2012's "Return") and screenwriter Mark Poirier (2008's "Smart People") might have made a tonally very different finished product, one driven by mean-spiritedness and the desire to watch its characters suffer. Instead, they use an initially cruel plot point as a means of exploring the human condition: the ability to forgive, one's propensity for compassion, and the longing that comes with wanting to love and be loved.

When the elderly lady she's been caring for passes away, Johanna puts the woman in her favorite blue dress and calmly calls to report the deceased. It is a process with which she is exceedingly familiar. Her next job—moving into the home where Mr. McCauley has been struggling to raise his grandchild since her mother's death—looks to not have quite the same grim outcome. Briefly after meeting Sabitha's father, Ken Gaudette (Guy Pearce), a ne'er-do-well addict attempting to piece his life back together and open a Chicago motel, Johanna is surprised to receive a letter from him thanking her for helping with his daughter. She pens a card back, but its journey to the mailbox is secretly intercepted by Sabitha's best friend, Edith (Sami Gayle). What follows is an increasingly intimate email correspondence. Renewed by the thought of a man showing interest and affection for her, Johanna begins privately making preparations to move to Chicago to be with Ken. What she does not know is that their relationship has been entirely fabricated, a deceptive charade perpetrated by Edith and Sabitha that has gotten completely out of hand.

"Hateship Loveship" is, first and foremost, a vehicle for Kristen Wiig's transformative range as an actor. She is extraordinarily touching as Johanna, a woman who lives through her work and cannot quite believe it when her email exchanges with Ken take on a flirtatiously soulful tone. Watching her grow in confidence and receive the false impression that they are meant for each other is heartbreaking as it unfolds because the viewer knows it is only a matter of time before she learns the truth. How director Liza Johnson allows this predicament to unfold is constantly surprising, particularly when Johanna finds herself abandoning her position and traveling to Chicago with her bags packed. What happens at this point is best left for each viewer to discover, but let it be mentioned once more that Wiig is wonderful, exquisitely modulating the many layers of a character who finds control and safety in taking care of others. The film leaves one wanting to learn more about Johanna and the things that have informed the person she currently is.

In a screenplay that paints its characters with shades of welcome gray, Guy Pearce (2012's "Lockout") plays Ken as a good guy in constant turmoil over his addictions. Some of his actions are less than savory, and he knows it—and doesn't like it. Although daughter Sabitha does not live with him and he doesn't get to see her as much as either would like, Ken retains a loving relationship with her. Hailee Steinfeld (2014's "3 Days to Kill") exhibits the complicated tug-of-war in Sabitha, a girl trying to navigate her way through adolescence. Rebellious but not snooty or belligerent , she has a healthy bond with her granddad and loves her father in spite of the troubling things they have experienced in their past. It is always nice to see Nick Nolte (2011's "Warrior") in a subdued turn; too frequently his deep, crackly rumble of a voice lends itself to stormier characters, but he can, in fact, do much more than play the heavy.

Sami Gayle (2012's "Detachment") sparks the screen with an edgy charisma as Edith, an immature girl who chooses to passive-aggressively bully Johanna under the fake identity of Ken as a means of supplanting her own insecurities. At first glance, the small roles played by Jennifer Jason Leigh (2013's "The Spectacular Now"), as Ken's bad-influence girlfriend Chloe, and Christine Lahti (2009's "Obsessed"), as bank teller Eileen, appear to not be worthy of such established veterans. Maybe they're not, but Leigh and Lahti were likely attracted to how non-stereotypically their characters have been imagined. In a lesser, more obvious film, Chloe would be portrayed as a low-life with a short fuse who blows up when she senses Johanna is shoehorning her way into their lives. How she instead reacts defies expectations, trusting that restrained behavior can have even more impact than an explosion.

"Hateship Loveship" is a low-key gem. Perhaps the scope could have been opened up more—there are a lot of interiors and only a handful of major shooting locations—but this closed-in feel affectingly lends itself to a heroine who has too long shut out the wide open world around her. Finding vitality in its ultimate neatness, the last ten minutes fit a lot of developments and personal triumphs into a narrow window of time, but does so beautifully. In much the same way, when it arrives, the confrontation between Johanna and Sabitha that is obviously coming skews in a totally different direction than what is anticipated. The film is better for it. The place where Johanna finds herself at the end of "Hateship Friendship" may or may not be wholly believable, but by then it scarcely matters. She deserves her happiness, and it has been a long time coming.