One would never expect director Christopher Alden to be merely trivial and he and Johann Strauss II, the Emperor of waltz and schmaltz, are hardly the most obvious bedfellows. His London/Toronto staging of the world's most popular operetta is, as expected, a dark and expressionistic interpretation that whips off the party mask to show the grinning skull beneath.
It may be the lightest and fluffiest of works but Die Fledermaus describes a ronde of marital infidelity, deception and retribution, which Alden revels in exploring. One might question whether the material really stands up to such treatment, and Alden's imagery is certainly difficult to decipher at times, but it scarcely matters, as his absurdist vision seeks above all to entertain.
Under the influence of a Dr Mesmer-like Falke (Richard Burkhard), Strauss's characters are whirled into a nightmarish world where pain threatens to overwhelm pleasure, and a vengeful vampire gloats over their discomfort.
From a usurped marital bed to an art-deco extravaganza of decadent revelling, the show gets more bonkers as the evening goes on and also more sinister, as high jinks give way to a last-act prison scene where rounded-up party guests are terrorised by an oleaginous Frosch and his band of strutting stormtoopers.
But, no matter how murky it gets, Alden at no point forgets this is a comedy. The dark undercurrents are laced with gags and irrepressible gaiety is ultimately allowed to triumph.
The problem of opera singers performing quicksilver farce is never quite overcome, harking back to the old days of hammy delivery and stomping movement, but the physical and comedic skills of Andrew Shore's cross-dressing Frank and Simon Butteriss's adeptly incompetent Dr Blind raise standards whenever they appear.
There's an excellent translation by Stephen Lawless and Daniel Dooner, full of ingenious rhymes and the odd contemporary reference. Sadly, surtitles are a necessity much of the time, with Jennifer Holloway's manic-depressive Prince Orlofsky suffering particularly from inaudibility due in part to a gloopy middle-European accent; it's fun but inscrutable, just like the whole show. A shame, as it's otherwise an extraordinarily good performance.
There are colourful characterisations from Julia Sporsén and Tom Randle as sparring spouses Rosalinda and Eisenstein and Edgaras Montvidas excels as a louche Alfred, spewing snippets of operatic arias in his underpants. Rhian Lois's ascent as a leading character singer continues with a bright and agile Adele.
ENO débutante Eun Sun Kim is a bundle of energy in the pit and the ENO Orchestra play Strauss's tuneful score with the right balance of finesse and abandon. This may be Die Fledermaus as never seen before but, true to the composer's intentions, it's a thoroughly enjoyable ride, with plenty of opportunity for Viennese-inspired psychological analysis if that's what you prefer.