CREATE TABLE table_18952 ("Ep. No." FLOAT, "Title" TEXT, "Director" TEXT, "Written by" TEXT, "Original Air Date" TEXT, "Production No." FLOAT)

What is the production number of 'rain of terror'?
SELECT MIN("Production No.") FROM table_18952 WHERE "Title" = 'Rain of Terror'
SELECT MIN("Production No.") FROM "table_18952" WHERE "Title" = 'Rain of Terror'