user: Question: Who directed episode number 18 in the series?
Columns: ['No. in series', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code', 'U.S. viewers (million)']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '" Pilot "', 'Ryan Murphy', 'Ryan Murphy, Brad Falchuk and Ian Brennan', 'May19,2009', '1ARC79', '9.62']
SQL:

assistant: SELECT "Directed by" FROM "Table" WHERE "No. in series" = 18.0;