Like any form of opera, contemporary British chamber opera has its clichés. Nameless characters, neutral locations; librettos in which lovers and enemies alike converse in gnomic aphorisms. Something about Capitalism (horrid!) and The Environment (lovely!). And of course someone’s always insane, or headed that way.

It’d be unfair to expect Stuart MacRae and Louise Welsh’s new opera The Devil Inside to avoid all those conventions altogether. What matters is how far the pair create something vital from them. The Devil Inside makes a strong start, with a terrific plot adapted from Robert Louis Stevenson. A bottle-dwelling imp can grant wishes - but must always be sold on for a lower price than that for which it was bought. Whoever owns it when they die loses their soul.

MacRae’s score is a superb creation in its own right: a study in deep greys and glistening silvers, capable of generating bizarre new colours (the lurid sound when the bottled demon shows itself, and the players in the 14-piece band blow mouth organs and bagpipe chanters), and of developing a real dramatic momentum – most notably in the closing scene, as the plot’s thumbscrew logic finally corners the central characters.

Michael Rafferty conducted like it was Mozart, while designer Samal Blak and director Matthew Richardson complemented MacRae’s sounds with stylish monochrome designs and understated characterisation. Imaginative use of projections created a suitably unsettling atmosphere: I could swear something was actually moving inside that glowing green bottle.

Meanwhile with singers of the calibre of Nicholas Sharratt (Richard) or Steven Page (suitably sombre-toned as the Old Man), MacRae’s surprisingly lyrical vocal writing alternately gleamed and threw long shadows. But Ben McAteer as James and Rachel Kelly as his wife Catherine gave the show its heart; her seductive poise giving way to anxious tenderness, and his early bluster rounding out into a loving and compassionate husband. Believable – even likeable – characters in a contemporary opera? That’s no small achievement.