Novocaine is used by dentists to dull pain. Another favoured method is nitrous oxide - laughing gas. In watching a black comedy starring Steve Martin as a dentist - Little Shop Of Horrors, anyone? - you might hope for a movie deserving of the name Laughing Gas.
Sadly, writer-director David Atkins has loftier ambitions in mind (a Hitchcockian 'wrong man accused' thriller, for starters), and Martin's usual 'wild n' crazy guy' is kept on a very short leash. Which seems a waste of the man's prodigious comedy talents.
Pitch-black comedy is, of course, the hardest thing to get pitch-perfect. When it works, as it does in several excellent scenes here, you get the gut wrench of violence followed by the uneasy release of a good belly-laugh.
When it doesn't work, as happens in several poorly-paced sequences here, a movie can flop around between incompatible styles, ending up being neither one thing nor the other.