His Suffolk fisherman is a timeless oracle, a drab sadist, a loser, a self-conscious contemporary symbol. Emotionally and musically, you cannot pin him down. He ought to be a figure of pathos, but you cannot pity his blind perversity. He seems to be waiting for a woman to redeem him, but you cannot credit Ellen Orford's devotion to such an empty shell of a man.
Herz turns the opera into a different work, telling of a tragic hero who is rejected and driven to his doom by an uncomprehending society. This other, conjectural opera would be a cliche and Britten did not write it.
For Herz, apparently, the score of Grimes is full of promptings for pretty, heart-warming spectacle: on Reinhart Zimmermann's tasteful sets in blacks, greys and browns, Herz marshalled his chorus into busy groups and had them swaying and jigging in time with the hornpipes, shanties and dances that lace through the music.
And indeed, the Scottish chorus was magnificent, quite equal to Britten's virtuosic demands in the off-stage passages, full of energy and vigorous projection on stage. They were matched by an orchestra with cold, gusty textures and a keen cutting edge, Richard Armstrong conducting with force and assurance.
The principals were fine - Anthony Rolfe Johnson a many- shaded Grimes, Rita Cullis rich, slow, persuasive as Ellen Orford, Russell Smythe a fiery Balstrode. Some of the smaller parts were excellent, too: Richard Halton sang with colour as Ned Keene, Patricia Boylan made the most of Auntie's ample physical presence, and the two 'nieces' - Anne Dawson and Ann Archibald - were delightful. Yet despite all this quality, no one ever seemed to make contact. Rolfe Johnson was hectoring in moments of anger and struggled vainly for restraint in the visionary passages, sometimes pitching his long notes slightly flat in an effort of painful expression. Ellen and Balstrode lacked any emotional commitment to him - their characters seemed quite self-contained, most telling in purely musical effects.
Still, this performance was enormously effective. The howling of the wind outside the 'Boar', the bell-chiming atmosphere of Sunday morning, the fury of the people as they set off to punish Grimes: all these moments were impressive. But in the midst of this theatrical splendour, Grimes seemed a stranger. There was no room for a man so ineffectual, so indecisive, so inconsistent. Professor Herz's production is a tightly-run ship, but Grimes is a shambles. He does not seem to belong on board.
Glasgow Theatre Royal (041-332 9000): in rep to 19 May, then touring