Based on Primary sources, I might go back to secondary material with new questions.
For example, newswires talk about alien-worshiping cults in the 1960s and 1970s, so I might go back to find articles and books about alien-cults.
Usually it's more focused (Ex a focus on just film or newspapers or diaries or etc)
I did several deep dives to give a sense of all the possible options -- you as historians won't usually try to cover everything at once.
