There were many good spots in the Kirov’s Ring, but I can only explain the third act of last night’s Götterdämmerung as some kind of delayed revenge for the Great Patriotic War. Hagen’s amnesia potion was so effective that the Siegfried forgot not only his wife but his lines. And as for the eponymous climax… well, I propose opera houses borrow a page from reality television and allow audiences to vote during the finale: If the Brünnhilde turns in a performance like Olga Sergeeva’s last night, the flames in the pyre are real.