As a young man, Antonín Dvořák (1841-1904) was playing viola in the Prague opera pit when Richard Wagner came to conduct his own music. The experience left its mark, notably in the most popular of Dvořák’s 10 operas, Rusalka (1900), with its Czech water nymphs, who are surely close cousins of Wagner’s Rhinemaidens. Garsington festival’s ambitious new production, complete with aerialists and tumblers, ropes, ladders and walkways, sinister inky pool and pre-dinner disembowelment, is at once natural and industrial, spectral and spectacular. Conducted by Douglas Boyd and directed by Jack Furness, it shows disturbingly how the tale of a water spirit who seeks light and life among humans mirrors our desires and our worst fears.