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This film works the same side of the street as novels like Stephen and Owen King's book Sleeping Beauties, Margaret Atwood's The Handmaid's Tale, or the films Children of Men, and A Quiet Place.
For an apocalyptic movie this film has few special effects. The story is woven tightly around two young lovers.
Many of us know people of both genders who express disdain and vitriol for the other gender. I think those are generally unfortunate opinions held by people with unexamined sexual/psychological issues. A dystopic story where one gender disappears shows us what we truly need from each other.

Will (Leslie Odom Jr.) and Eva (Freda Pinto) are a loving couple. A comet passes over the world. For a period of time (the film jumps around chronologically), the comet produces ash which falls across the planet. Although it looks like snow, it's not.

This ash contains a bacteria or virus that occasionally infects but does not kill men or boys. Men can infect women. But the pathogen kills women and girls. Some women live longer than others but with one possible exception there aren't any women who are immune. Females die by the multitudes. Humanity faces its end. Governments create medical centers to find a cure. But everyone suspects that the centers are not designed to help women so much as they are built to harvest eggs and find a way to mass produce artificial wombs. Women and girls have become so rare that the US government is offering million dollar bounties for the delivery of a live female. Initially the bounties are only for women of child bearing age but eventually armed government agents search for females of any age. Thugs search for women for other reasons.

Will refuses to turn over Eva to the government. The formerly genial, soft-spoken, and decidedly non-bada$$ Will intends to keep Eva safe.
Will takes this responsibility seriously, to the point of building a complicated "stay in place/quarantine system". Will will kill and die for Eva if needed. Eva may be the last woman in the world.

Although Eva appreciates Will's protectiveness she thinks he's become monomaniacal. Eva resents and occasionally resists some of Will's decisions.
As in many emergency situations, both individual and societal, democracy falls by the wayside. Will struggles with his girlfriend's unhappiness and challenges while trying to keep them both safe.
Is it, during times of stress and conflict, automatically the man's role to provide and protect? If so can the woman question her man's leadership if doing so can get them both killed.

This was an intelligent movie that demonstrates that sci-fi/speculative fiction doesn't need to rely on cheap thrills, gore and T&A. One big narrative weakness was that it is utterly pointless ever to attempt to disguise Freida Pinto as male. Even the dimmest man would immediately recognize that Eva is female. There's nothing that is androgynous about Pinto. Also, this film could have benefited a LOT from a shorter running time and a larger budget. Lighting was bad too often. This wasn't a home run must see film. But neither was it garbage. Only nimbly demonstrates how intimates communicate wordlessly with each other. Will and Eva love each other desperately, even as their relationship is strained to the breaking point. There is constantly rising tension and drama but little violence.

"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming

Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.