CREATE TABLE table_24757 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "U.S. viewers  ( millions ) " CLOB)

How many number of series have the title 'call of silence'?
SELECT "No. in series" FROM table_24757 WHERE "Title" = 'Call of Silence'
SELECT "No. in series" FROM "table_24757" WHERE "Title" = 'Call of Silence'