What number in series is "Diamonds"?
CREATE TABLE "table1_21666472_1" (
  "no_in_total" text,
  "no_in_series" text,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text
);
SELECT "no_in_series" FROM "table1_21666472_1" WHERE "title"='\"Diamonds\"';