The single location, the reliance on dialogue and the real time aspect all make Inserts feel like a filmed stage play - artfully filmed with a sallow, sepiated tint - but a stage play all the same.
Dreyfuss plays that genius in a dirty bathrobe, a bottle of booze in one hand and a suffocating cloud of despair over his head.
But once you sink into that rhythm the film becomes a hypnotic march towards doom.
The opening sets such an incredible tone for everything to come: the young people laughing at this silly, stupid porno, one that we know came from such incredible sadness.
His biggest and best scene is opposite Harper, as he first coaxes her to get naked and then finds himself seduced by her wit and intelligence.
That means the film is sometimes slow, stopping to let Boy Wonder pontificate.