This is unassuming and yet amazing film making. Two young men are companions together on their spiritual mission-work as Mormons, assigned to spend day and night together as they attempt to spread the Mormon faith, and several copies of The Book of Mormon, through the small-town Pacific northwest. Honestly, if one were not told this was a gay and lesbian film, their eventual relationship would come as an unheralded surprise, it's handled so subtly and sensitively. It follows their admittedly dull days as missionaries, lets a slow tenderness develop between them, and doesn't ruin any of its own surprises as their understated love develops. We only find out as they tell each other, almost halfway through the film, that their reticence and silence all along have cloaked same-sex affections within the not-at-all-accepting Church of Latter-day Saints. Their relationship is one of the subtlest gay love stories in modern queer film, their depicted lives are as as uneventful as actual afternoons of missionary-preaching would be, and neither man is any more articulate than you expect of repressed, closeted, anguished gay youth. One has to give this slowly building, lazily paced, ultimately unexpressive story its own time to unfold, without giving away any of its secrets. Once one appreciates that, even this movie's reticence can be seen to strike exactly the right note.
Other here have faulted the two leads for not showing chemistry with one another, but I think we look for chemistry in a screen-couple in heterosexist ways, and we get this couple's chemistry wrong in the same way people missed the chemistry between the leads in _Brokeback Mountain_. These men in their repressed environment couldn't _show_ open, chemical affection for one another. That mainstream audiences can't see it doesn't mean it isn't there among gay male couples. It means they're succeeding in hiding it, for the other, homophobic missionaries within the story, and even for audiences who aren't attuned to it as they watch the film. If you've never had to hide your own affection for a same-sex amour, perhaps you don't appreciate the lengths people go to to hide chemistry from others, and even to hide it from less perceptive viewers of this film.
Give this film a chance, and perhaps have more patience with its plodding development than you would with blockbusters, or even with more conventional gay and lesbian films. Its subtlety is actually its strongest suit. The wait for its eventual revelations is the sweetest part of this under-appreciated film.