If ever there was a movie that felt cinematic, Lost Butterfly would be it. The second of three films based on the Sakura Route of the original Fate/Stay Night visual novel, the camera work and animation combine to present us with a feeling of the immense scope of the Grail War, even as it plays out in one relatively small place and time. Although the stakes are only high for a miniscule group of people (if we discount all the citizens who are unwittingly living through things), their intensity is never minimized, and we're made to feel that to Shiro, Rin, Sakura, and Ilya, the events of their corner of the world might as well be those of the entire globe in terms of the stakes, both physical and emotional. To call the production overall “impressive” is almost to make an understatement.

That said, this is the second of three films adapting the third of three routes from the original visual novel, and that means that familiarity with those other pieces is highly recommended. Knowing the events of Fate/Zero will also be helpful, although it's not strictly necessary, as the pertinent information from it originates in this arc. The way that all of the pieces of the story twist together to form a whole is certainly one of the most interesting features of the multi-route visual novel as a storytelling medium in general, so that's something to consider before viewing, assuming you are interested in this as more than a chance to see this particular heroine's story play out.

As a heroine, Sakura has the least agency of anyone in the series with that title. That this is in no way her fault is laid out in this film very clearly. As a child of the Matoh family, and the one with stronger mage blood than her older brother Shinji, the ostensible heir, Sakura has been subjected to a lifelong litany of the ways that she is “inferior” and “impure.” As part of this process, she has been parasitized with something called “crestworms,” which are basically a magic parasitic bug (in the sense of both an insect and a computer virus), and this has had an adverse effect on her ability to control her own powers. But more importantly for Sakura as a person, she's also been subjected to the virtual and more insidious parasite of her own lack of worth – when she tells Shiro that she's impure in body, we can all make an educated guess as to who's responsible for that (hint: it's not Grandpa) and that she has been sold on the theory that she is, in fact, to blame for her own rape. Sakura firmly believes that, even as she and Shiro become closer both emotionally and physically, and this self-hatred and self-recrimination is ultimately behind her slide into darkness as the film moves towards its close. She's been so poisoned by the Matohs that she can barely see her actual self through the haze, and in some ways the reveal of what she's been doing and who/what she has become are the only way she sees left for herself to reclaim herself. If she's an impure monster, then maybe she should just be that creature, because after all, being sweet Sakura didn't save her and barely brought her anything beyond fleeting moments of happiness.

That questions of humanity are periphery parts of this film is perhaps unsurprising. The Matohs have long viewed Sakura as a sort of reliquary for magecraft, and Shiro's continuing service to humanity becomes one of Archer's key concerns as the movie progresses. Archer may be said to be worried about his own future existence, but he also seems to be wondering if Shiro's interactions with Sakura aren't making him too human – willing to throw over noble ideals of saving the world in order to save a single girl. Shiro certainly does seem to be headed down that path, although whether or not he's thinking of the consequences is debatable; by the time he sleeps with Sakura it's clear that he's thinking in a different way than he was previously, but also that he might not be fully aware of that fact. It's worth keeping in the back of your mind for the third film, in any event, especially with the increased presence of Ilya and the changes to Shiro's physical body.

This is, hands down, the scariest route, or at least the rendition that best plays with the original game's horror aspects. That means that this comes with a warning for people who have an issue with bugs, both singly and in huge, horrible whirlwinds of insect activity, but also that there's a definite increased focus on the bloodier elements of the story. It's not a gore-fest by any means, but the gorgeous animation and art does mean that it stands out in a way that a film with lesser production values would not have. The imagery is effective, though – Sakura's Disney-inspired dream sequence is fascinating on several levels and Shiro's steady walk towards her in the rainy park is more powerful than you'd expect. The sex scene isn't too explicit, however – it's tastefully done while still being a few steps above what you'd expect to see in TV anime.

While on-disc extras are pretty thin – they're basically a collection of commercials in both English and Japanese – the physical extras are very nice. The box itself is understated and lovely (although it shows fingerprints easily), and there are two books included – a hardcover artbook and a paperback collection of interviews and production notes. There's also a soundtrack disc and a trading card for the franchise-associated game, as well as a coupon code for another. The artbook is easily the standout here, assuming you don't favor interviews; there are some gorgeous images of the female cast in a variety of enticing outfits.

Lost Butterfly is not an easy-viewing movie. It's dark, shows a character slowly twisting into darkness as her only possible recourse, and it's got some upsetting imagery. But it is a good story, ably adapting the source material and combining it with strong vocal casts, beautiful animation, and a soundtrack enhances the story. If you enjoyed the first film in the trilogy, there's no reason not to pick this up.