Question: What was the season number for production code E2110?
SQL: SELECT "Season no." FROM "1-21781578-2" WHERE "Production code" = 'E2110';

Question: What was the original air date for season number 2?
SQL: SELECT "Original air date" FROM "1-21781578-2" WHERE "Season no." = 2.0;

Question: What was the season number episode directed by John David Coles?
SQL: SELECT "Season no." FROM "1-21781578-2" WHERE "Directed by" = 'John David Coles';

Question: What was the number of US Viewers in the episode directed by Steve Shill and having a production code of E2102?
SQL: SELECT "U.S. Viewers (millions)" FROM "1-21781578-2" WHERE "Directed by" = 'Steve Shill' AND "Production code" = 'E2102';

Question: What was the number of season number entries that had US Viewers of 12.30 million?
SQL: SELECT COUNT("Season no.") FROM "1-21781578-2" WHERE "U.S. Viewers (millions)" = '12.30';