Jodorowsky's Dune Uncovered
Scene 92 : Alia's Conception
The Harkonnen soldiers guarding Gurney Halleck in the desert have run out of water, and one decides to kill him.
As he moves towards Halleck an arrow pierces his throat, and the other guards are also quickly killed by a group of smugglers lead by Emmer Tuek, who releases Halleck.
Meanwhile, Paul and Jessica hear an approaching 'thopter and they hide among the rocks. The 'thopter appears and a box is thrown out of it, smashing on the rocks, scattering the limbs of Leto.
When the 'thopter has passed Paul and Jessica run up to the remains and fall to their knees. Jessica rearranges the pieces back into the shape of a body and tell Paul "Let me change death into life".
Paul sits on a small hill with his back to Jessica as she lies naked on top of Leto.
In a deleted scene on the Jodorowsky's Dune documentary Blu-ray/DVD we see Alia's conception playing out similar to the script, although instead of simply laying on the Duke, Jessica instead presses her head to his and a foetus moves from Leto's head into her womb.