SELECT "Title" FROM table_663 WHERE "Directed by" = 'David Duchovny'
What episode was directed by David Duchovny?
CREATE TABLE table_663 (
    "No. in series" real,
    "No. in season" real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "Original air date" text,
    "U.S. viewers (million)" text
)