Table: episodes_viewers
Columns: no_in_series
no_in_season
title
directed_by
written_by
original_air_date
u_s_viewers_millions

Question: What is the number in the season that Marlene Meyer wrote and 20.49 million people watched?
SQL: SELECT MAX("no_in_season") FROM episodes_viewers WHERE "written_by" = 'Marlene Meyer' AND "u_s_viewers_millions" = '20.49'

Question: When did the no. 23 show originally air?
SQL: SELECT "original_air_date" FROM episodes_viewers WHERE "no_in_season" = 23