The camera finds Olivia Cooke’s face first — through rain on glass, in the particular gray light that Seattle wears like a coat it refuses to take off. Little Fish begins in the middle of things, which is also where it lives. Chad Hartigan’s film does not open the way most pandemic narratives open, with the architecture of catastrophe and the wide shot of an emptied world. It opens with a woman trying to remember the name of something she loved.

The virus in this near-future — NIA, for Neuroinflammatory Affliction — erases memories. Not dramatically, not all at once. It takes them the way fog takes a cityscape: gradually, from the edges in, so that by the time you notice the absence you cannot quite reconstruct what was there. Mattson Tomlin’s screenplay, adapted from a short story by Aja Gabel, structures the film with the same logic: the chronology slides, loops back, loses itself. Emma (Cooke) and Jude (Jack O’Connell) exist in multiple tenses at once, and the editing trusts the audience to find them there.

What Hartigan and cinematographer Sean McElwee do with Seattle is quietly remarkable. The city appears as a place already halfway to dissolving — water on every surface, light that cannot decide between dawn and dusk, compositions that keep their subjects slightly off-center, as though the camera itself is uncertain where to look. This is a film about forgetting, and every visual choice reinforces it without being so obvious as to feel instructional. The city does not announce what it represents. It simply looks the way the feeling of forgetting looks.

Cooke and O’Connell are the reason Little Fish works in the ways that it does. Their chemistry is not of the kind that announces itself — there are no grand gestures, no scenes designed to demonstrate feeling. What they build instead is something quieter: a relationship that has the texture of duration, of accumulated habit and specific knowledge. When Jude begins to lose pieces of himself, and Emma watches it happen, the loss is not abstract. We have seen enough of what is being lost to feel it.

The film is not without its costs. Pacing sags in the middle third, where the non-linear structure can feel like a strategy rather than a necessity. The science-fiction machinery — the pandemic bureaucracy, the experimental treatments — remains deliberately thin. Hartigan is not interested in the mechanics of the plague; he is interested in what it feels like to love someone who is disappearing. That focus produces the film’s best passages and also its most frustrating ones.

Little Fish arrived in February 2021, when its pandemic allegory was almost too on the nose to absorb. Its resonance has outlasted that coincidence. Hartigan made a film about the specific terror of watching memory — which is to say, identity, which is to say, love — dissolve in someone you cannot afford to lose. Whether the vehicle is a fictional virus or a real one turns out not to matter much. The film aches. That is the point.