CREATE TABLE table_24121 ("Episode" TEXT, "Broadcast date" TEXT, "Run time" TEXT, "Viewers  ( in millions ) " TEXT, "Archive" TEXT)

What episode had a run time of 23:38?
SELECT "Episode" FROM table_24121 WHERE "Run time" = '23:38'
SELECT "Episode" FROM "table_24121" WHERE "Run time" = '23:38'