Blurring the boundaries between documentary and fiction is hardly a novel notion. But this genre-defying drama from debuting director Anna Odell is something strange, something wonderful, something never seen before.

A game of two halves, the first section opens with the get-together of the title, an occasion defined by jollity, small talk and speeches that are less humorous than the speaker imagines. The polite nostalgic mood tone of the evening is rewritten when Anna (Odell) stands up to denounce her former classmates as cruel or indifferent tormenters. Prepare to watch through your fingers as she repeatedly reiterates her claims.

A concluding chapter chronicles the writer-director's attempts to show and discuss her film with the classmates portrayed. It is as revealing as it is impactful. Many are calling The Reunion the new Festen . Much as we love Thomas Vinterberg's evergreen drama, this is stronger still.

Odell, a multi-hyphenate artist who came to prominence after a restaged suicide attempt in Stockholm, has crafted a taut conversation-starter that will keep you guessing as to where reality ends and art begins. Long before Laurie Anderson's similarly indiosyncratic Let X = X/IT Tango strikes up over the closing shots, we suspect this will be your favourite film from the entire JDiff 2014 catalogue.