CREATE TABLE table_26441 ("No. by series" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "Production number" FLOAT, "U.S. viewers  ( in millions ) " CLOB)

Who directed the episode titled 'Ghosts'?
SELECT "Directed by" FROM table_26441 WHERE "Title" = 'Ghosts'
SELECT "Directed by" FROM "table_26441" WHERE "Title" = 'Ghosts'