My Ring review cites Wagner's stage directions for the end of Goetterdaemmerung, noting that there's no reason to invent action for the orchestral coda. Realizing that not everybody has the libretto handy, here they are, forthwith, with bits of the Immolation text as guideposts.
(alone in the center [of the stage]; after remaining long absorbed in contemplation of Siegfried's face, first with profound shock, then with almost overwhelming despair, she turns to the men and women in solemn exaltation. To the vassals:)
schichtet mir dort
Vollbringt Bruennhildes Wunsch!
(During the following, the younger men raise a huge funeral pyre of logs before the hall, near the bank of the Rhein: women decorate this with coverings on which they strew plants and flowers. Bruennhilde becomes again absorbed in contemplation of Siegfried's body. Her features become increasingly transfigured with tenderness.)
Wie Sonne lauter
strahlt mir sein Licht;
Wisst ihr, wie das ward?
(looking upward [and addressing Wotan])
O ihr, der Eide
Ruhe, ruhe, du Gott!
(She gives a sign to the vassals to bear Siegfried's body on to the pyre; at the same time, she draws the Ring from Siegfried's finger and gazes at it thoughtfully.)
Mein Erbe nun
nehm ich zu eigen
Ihr in der Flute
loeset ihn auf,
und lauter bewahrt
das lichte Gold
das euch zum Unheil getaubt.
(She has placed the Ring on her finger, and now turns to the pile of logs on which Siegfried's body is laid. She seizes a great fire-brand from one of the vassals and gestures towards the back.)
Fliegt heim, ihr Raben!
in Wahlhalls Prangende Burg.
(She flings the brand on the pyre, which quickly breaks out in bright flames. Two ravens fly up from the rocks on the shore and diappear in the background. Bruennhilde sees her horse, which has been led in by two young men. She hasten towards it, takes hold of it and quickly removes the bridle; then she leans over it confidingly.)
Grane, mein Ross!
Selig gruesst dich dein Weib!
(She has mounted the horse and leaps with a single bound into the blazing fire. The flames immediately blaze up so that they fill the whole space in front of [Gibichung Hall], and appear to seize on the building itself. The men and women press to the extreme front in terror. When the whole space of the stage seems filled with fire, the glow suddenly subsides, and only a cloud of smoke remains; this drifts to the background and lies there on the horizon as a dark bank of cloud. At the same time, the Rhein overflows its banks in a mighty flood which pours over the fire. On the waves the three Rheinmaidens wim forward and now appear above the pyre. Hagen, who since the incident of the ring has observed Bruennhilde's behavior with increasing anxiety, is seized with great alarm at the appearance of the Rheinmiaidens. He hastily throws aside spear, shield, and helmet and rushes like a madman into the flood.)
Zurueck vom Ring!
(Woglinde and Wellgunde twine their arms around his neck and draw him with them into the depths as they swim away. Flosshilde, swimming in front of the others toward the back, joyously holds up on high the regained ring. Through the cloudbank, which has settled on the horizon, a red glow breaks out with increasing brightness. By its light, the three Rheinmaidens are seen, swimming in circles, merrily playing with the ring on the calmer waters of the Rhein, which has gradually returned to its bed. From the ruins of the fall hall, the men and women, in great agitation, watch the growing firelight in the heavens. When this reaches its greatest brightness, the hall of Valhalla is seen, in whcih gods and heroes sit assembled, just as Waltraute described in the first act. Bright flames rise on the hall of the gods. When the gods are entirely hidden by the flames, the curtain falls.)
Now, I own that there is a shortage of sopranos willing to ride a horse onto a flaming funeral pyre, not the mention animal welfare laws and fire marshalls that frown on such behavior. What Wagner has prescribed would be tough to stage even for Cirque du Soleil, with its shows set in giant tanks of water. But film technology makes it eminently do-able after Bruennhilde sings her last and vanishes from the stage, horse or not.
The Wadsworth Ring, most of which I saw in Seattle in 2001, came close to realizing the instructions - though again, the gods in Valhalla looked like a family reunion rather than the end of the world: too much Kumbaya for me.