CREATE TABLE table_26433 ("No. by series" FLOAT, "No. by season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production number" FLOAT, "U.S. viewers  ( in millions ) " TEXT)

What is the series number of the episode 'Pandora'?
SELECT "No. by series" FROM table_26433 WHERE "Title" = 'Pandora'
SELECT "No. by series" FROM "table_26433" WHERE "Title" = 'Pandora'