His most recent job involves a complicated multi-source recording of a couple most likely having an affair talking as they walk in a busy city square.
When he goes to drop the tape off he gets a strange vibe from the client's PA (Harrison Ford) so leaves again with it and decides to go over the originals furhter to see if he can extract any more from the garbled sections.
No good will come of this.
Great paranoid stuff from Coppola. The conversation in question and Harry's past get revealed slowly teasing you with the source of his unease.
It's slightly padded with interactions with colleagues and rivals at a trade show and afterparty but if that were missing you'd lose some context and it'd be very short.
Harry is a lonely tragic figure who in a modern movie would probably be recognised as on the spectrum somewhere and when things start to go wrong he's nobody really to turn to, not even his faith.
Recommended 8/10.