This answer has a lot of images that I shouldn't need to repost here, and is supplemental to this answer to the question Help me understand what Farside, a ten “stage” rockoon looked like? How was it configured?
All available sources quoted in both answers state that Farside is a four stage rocket, with the 3rd stage being four parallel Asp's and 4th stage being a single one. But all images shown in both answers just seem to show the four cores of the 3rd stage topped with what looks like a large badminton birdie which is the payload.
Where is the fourth stage?