A Home at the End of the World, the bittersweet tale of an unconventional relationship, is a challenging film that comes at a time when the country is divided over issues of what constitutes "acceptable" marriage and parenting, lending the film a particular and timely substance. Charting the lives of two male best friends and the woman who becomes an integral part of their lives, the strengths of A Home at the End of the World lie principally in its richness of character and performance. It’s certainly an efficiently made film, decent looking and filled with color. But this is a film about performances.

Teenagers Jonathan and Bobby meet in a Cleveland High School in the 70s, and couldn’t be more opposite. Straight-laced, geeky Jonathan is the product of a traditional, conservative upbringing, while Bobby is a product of 60s liberation, drug culture and a hippie household broken by tragedy. They immediately connect as Bobby finds security in Jonathan’s middle-class home and slightly disillusioned mom, Alice (Sissy Spacek), while Bobby’s charisma, casual pot smoking and sexual availability liberate Jonathan. Orphaned Bobby joins their household and the boys are inseparable.

As young adults, Bobby (Colin Farrell) stays back in Cleveland with Jonathan’s parents while Jonathan (Dallas Roberts) goes off to New York for school, eventually settling down with Clare (Robin Wright-Penn), an offbeat East Village hat-maker who yearns for a baby. After Bobby arrives in New York and moves in with the two, complications ensue.

But the film isn’t content to be just a romantic roundelay. The excellent script by Michael Cunningham (The Hours) moves forward in time to the birth of a child, exploring the ties that bind the three, as they live together to parent "their" child. It is refreshingly free from the obvious comic hijinks that usually accompany such material, and it takes an honest glimpse into the difficulties of creating and maintaining family love in their fiercely loyal, original household.

A Home at the End of the World is loaded with good dialogue, endearing characters and delicately fragile moments so sad they might make your heart stop. But it’s also a very true film about how relationships defy categories and human beings connect in unpredictable ways, unable or unwilling to be limited by traditional definitions.

As sensitive Bobby, Farrell, of the hard-drinking, anything goes reputation, immerses himself so deeply into a character so innocent, faithful and good that he makes us wish we all had someone so true. Though Jonathan is openly gay and Clare is straight, Bobby isn’t defined by any particular sexual identity, and indeed Farrell’s big achievement here is how believably he creates a person who simply loves, exclusive of any sexual orientation.