CREATE TABLE table_23982399_1 (overall_episode__number NUMBER, original_airdate VARCHAR2)

What episode number originally aired on November 21, 1993?
SELECT MAX(overall_episode__number) FROM table_23982399_1 WHERE original_airdate = "November 21, 1993"
SELECT MAX("overall_episode__number") FROM "table_23982399_1" WHERE "November 21, 1993" = "original_airdate"