It's a bit of a running joke that, whenever my best friend Nick and I go on our adventures, extraordinary things always happen. So perhaps we should have warned the Glyndebourne management I was taking him for his first visit there on Friday. For during the performance itself real-life drama outshone artifice. Though Dvorák's Rusalka and Disney's Little Mermaid draw upon the same fairy tale for inspiration, the similarities usually end there. This time there was a cartoonish quality to events in the opera house too. Melly Still's production uses a troupe of dancers and tumblers to provide a degree of grace and athleticism one rarely sees on the operatic stage and, as we approached the close of Act One, the action went a little too far. Ana María Martínez, playing the eponymous Mermaid, approached the very edge of the stage, became tangled in some of the netting used to simulate the sea bed and, in extraordinary slow motion, struggled not to tumble forward. For one fleeting moment it was possible to believe – and hope – this was just another part of the ambitious staging, but then, with a scream and a sickening crash, the leading lady landed plumb onto the 'cello section of the London Philharmonic Orchestra. In moments the house manager was on stage asking the time-honoured and inevitable question "is there a doctor in the house?" and the audience were asked to clear the auditorium, a backward glance suggesting the situation was serious, with anxiety-bordering-on-distress etched on the furrowed brow of co-star Brandon Jovanovich, who had been powerless to stop the dramatic plunge. An extended interval followed as excellent understudy Natasha Jouhl was upgraded from First Nymph to lead and her own understudy was, in turn, rushed down from London. A superb performance ensued, the audience having been reassured Ana María Martínez had been kept in hospital only as a precaution. All in all, a night none of us will ever forget – particularly Natasha Jouhl, after the extended, fully merited standing ovation she received. As ever, the show must go on…