user: Question: Who directed episode number 23?
Columns: ['Episode No.', 'Series No.', 'Title', 'Directed by', 'Written by', 'Viewers (millions)', 'Original airdate']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: [23.0, 1.0, '"Better the Devil"', 'Ben Bolt', 'Jack Lothian', '8.30', '20 September 2009']
SQL:

assistant: SELECT "Directed by" FROM "Table" WHERE "Episode No." = 23.0;