Table: episodeseries_2
Columns: episode
series
episode_title
original_air_date
production_code

Question: When "the secret of deep stadium" is the episode title what is the lowest series number?
SQL: SELECT MIN("series") FROM episodeseries_2 WHERE "episode_title" = '"The Secret of Deep Stadium"'

Question: when 68 is the episode number what is the series number?
SQL: SELECT "series" FROM episodeseries_2 WHERE "episode" = 68

Question: when 69 is the episode number what is the air date?
SQL: SELECT "original_air_date" FROM episodeseries_2 WHERE "episode" = 69