Table: tv_episodes_31
Columns: series
title
director
writer
air_date
production_code

Question: When did the episode "rowley 1898" air?
SQL: SELECT "air_date" FROM tv_episodes_31 WHERE "title" = '"Rowley 1898"'

Question: What was the production code of the episode written by Brendan Cowell?
SQL: SELECT "production_code" FROM tv_episodes_31 WHERE "writer" = 'Brendan Cowell'