Das Rheingold
Royal Opera House performs Das Rheingold. roh.org.uk
From Royal Opera House website:
The dwarf Alberich forsakes love so that he may steal the Rhine’s gold. A ring is crafted from that gold, invested with great power. When the ring is taken from Alberich, he places on it a terrible curse.
The god Wotan is tempted by ownership of the ring – but heeds a dire warning from the goddess Erda. Instead, Wotan uses the ring to pay the giants Fafner and Fasolt for building his palace Valhalla. Alberich’s curse takes immediate effect: Fafner kills Fasolt so that he may keep the ring for himself.