Who directed the episode titled "Jack and the Zombies"?
CREATE TABLE "table1_2156758_4" (
  "no_in_series" text,
  "no_in_season" text,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text
);
SELECT "directed_by" FROM "table1_2156758_4" WHERE "title"='\"Jack and the Zombies\"';