It characterises that monarch-substitute, the Duke, as the embodiment of rule by absolute whim and shady purpose. This fascinating outline idea cries out for development, for performances that bolster this concept, rather than the superficial work of James Laurenson, Richard Dormer and Andrea Riseborough, respectively fighting it out as the Duke, his deputy Angelo and Isabella, the novice for whom both men have the illicit, unreciprocated hots.