Arnott - whose public absence from the scene for the last six years says much about the Scots commissioning process - has set his psychosexual nightmare scenario squarely in the back closes of Edinburgh by night, exploiting the inherent theatricality such rich geographical pickings can bring to a piece. Steve McNicol's flamboyant Hyde literally cruises the streets with gay abandon, flaunting his deviance rather than shrouding its dubious light beneath respectability's ever-present bushel.
This is to be found instead in the drawing-room talking shops frequented by Andrew Dahneyer's Jekyll and other apparently enlightened types. Their hunger for knowledge begins and ends with the hot-air theorising and empty rhetoric of the privileged set who take on the mantle of explorers because they have nothing better to do.
The first half of Hamish Glen's production is as faithful to the horror / thriller genre as it can be, moving back and forth in time, dropping clues, then picking them up from other angles at crucial moments in the plot. Hyde is woozily filmic in this way, and sets up a brilliantly scary atmosphere, especially with the symbolic graffiti smeared and scrawled on to every available surface so as to beam down on to the action with iridescent foreboding. Never has the phrase "written in blood" seemed more appropriate.
This atmosphere, though, is never fully put to the test in the slightly muddled second half. Hyde's message about society's outsider - from junkie to Jew to bisexual - is clear enough, but when "good" ends and "evil" begins is never clearly defined, as the twin personalities overlap and then supersede each other without ever seeming to care about what they're doing.
The action appropriately takes place on twin multi-tiered revolves, which, as they suitably squeak through every laborious inch of their circumference, seem to delve further and further into the murky canyons of the mind we all have the potential to unleash. Arnott's argument is as black and white as that. Without a doubt though, it falls firmly on the dark side. And that's where truth lurks.