I tried to deal with the action in this way:
I had set up the intentions of the WiKi earlier by some hammy dialogue where he intended to enslave the hobbit with a Morgul knife.Cut to two black-robed figures standing motionless at the edge of the dell. They glide smoothly, ghost-like and slowly towards the camera. Cut to a view of the dell. Strider takes two torches and advances towards the black figures. They circle around him avoiding his attacks and draw him away. Three more figures, one of them much taller, appear at another point on the edge and move swiftly towards the hobbits. Two halt to stand guard against Strider while the tall one continues. Cut to the hobbits staring. Pippin screams, throws down his torch and hides his face against Merry who protectively covers him and then turns his face in fear too. Sam closes up to Frodo. Cut to Frodo alone, his face is agonising. He pulls out the Ring and puts it on and vanishes. Cut to a tall crowned figure clad in grey armour walking to the camera. His face is gaunt and blank and almost transparent. His eyes are large, unnatural and unsettling and staring. He is illuminated in a sickly greenish white light. In his hand is a long thin slightly curved knife. Cut to a view of the Witch-King approaching Frodo. Frodo is bright and glowing golden. The Ring pulses with light on his hand. All his friends appear as dim dark shadows. The fire burns with an intense redness. We are seeing the scene in the Spirit world. Frodo draws his sword against the advancing figure and the blade flickers blue.
Cut to a view from behind Frodo as the Witch-King advances.
Frodo: 'O Elbereth Gilthoniel!' He slashes wildly and vainly at the legs of the Witch-King then huddles in fear on the ground. The Witch-King bends over him and sticks the knife in Frodo's shoulder. A thin high-pitched girlish shriek of pain is heard. The Witch-King bends the knife to one side to snap off the tip and then tosses the blade aside.
Witch-King: 'Come to me!' He turns and moves swiftly away and Frodo vanishes.
Cut to a normal view of the dell. Sam is bending over Frodo. Merry and Pippin huddle together. Strider runs back towards them. The tall black-garbed figure of the Witch-King pauses for a moment to watch him approach then swiftly moves away. Strider plunges his torches into the pile of brushwood which flares up into an immense blaze. He runs off over the edge.