About two thirds completed - a couple of shoves may get me going again.
23d) Novel by a contemporary of Hemingway ("Papa") and another American author (4) *N*N
20a) I was once privileged to take two of every seven in lunar excursion modules (6) **C*M*
21a) Rada's rival for drama in conspiracy theory writer's case (8)
The solution is QALAMDAN but how does QAN define conspiracy theory? I am aware of QAnon obviously.