Like love, grief is one of those things that, though close to a universal experience, is almost impossible to explain. Mix in feelings of guilt, take away other people, and it can feel like the end of the world.

Except that for Aubrey (Virginia Gardner), the heroine of Starfish, it actually is the end of the world. After attending her best friend Grace’s funeral, Aubrey breaks into her flat and wallows there in crushing sadness. After a day or so, she wakes up to what looks a lot like the apocalypse, and continues to be plagued by horrific dreams, hallucinations and other strange goings-on. When she finds a mixtape left by Grace, she must reckon with her role in possibly saving the world.

Starfish is almost an impossible film to spoil, but we’re still reluctant to explain too much. It is first and foremost a film that wants you to experience it. Unconcerned with plot or the obvious sci-fi potential of its story, director Al White uses gorgeous visuals and a darn good soundtrack to convey the ways in which human loss and an apocalypse might feel like the same thing from a certain point of view.

The fact that we don’t know the cause of Grace’s death makes her absence from Aubrey’s world all the more powerful. Any loss is potent for those who loved the deceased, but to lose a peer can trigger a different kind of crisis.

Gardner, who you may recognise from Marvel’s Runaways, is excellent in a role that demands she carry every frame. Particularly engaging is a sequence in which she decides that no more people is a great thing, and commits to hanging out with a pet turtle and reading all of the books she never had time for before. Who is this oversaturated, busy world hasn’t had that fantasy?

There are huge swathes of the film that echo other low-budget indies like Monsters, with Starfish using its genre as background dressing rather than the main point. There are jump scares, but they serve to make the audience pay attention rather than to frighten. The creatures are also used sparingly, abiding by the old rule of only showing what you have to when the film demands.

You may want Starfish to be a more traditional film, but to do so would be to misunderstand its intentions. The end of the world both is and isn’t a metaphor for grief. It is and isn’t happening in the real world. The only facts we really know are that Grace is dead and Aubrey is processing her death.

But within all this vagueness, filmic experimentation and ambiguity, Starfish is a moving portrait of loss and a brilliant showcase for both its director and its star.

Starfish screened at Raindance Film Festival in the UK and at Fantastic Fest in the US.