Question: Who wrote episode 31 in the series?
SQL: SELECT "Written by" FROM "1-21831229-3" WHERE "No. in series" = 31.0;

Question: What was the date that the episode with a production code of 213 was originally aired?
SQL: SELECT "Original U.S. air date" FROM "1-21831229-3" WHERE "Prod. code" = 213.0;