Who wrote the movie positioned at 8 on the list?
CREATE TABLE "table1_2602958_5" (
  "no" real,
  "num" real,
  "title" text,
  "director" text,
  "writer_s" text,
  "original_air_date" text,
  "prod_code" real,
  "u_s_viewers_million" text
);
SELECT "writer_s" FROM "table1_2602958_5" WHERE "num"=8;