user: ### NOW ANSWER:
Question: tell me the writer of production code AD1D09.
Columns: ['Title', 'Directed by', 'Written by', 'Original air date', 'Production code']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['" Mystic "', 'Don Colliver', 'Peter Field Rachael Ray', 'January21,2005', 'AD1D02']
SQL:

assistant: SELECT "Written by" FROM "Table" WHERE "Production code" = 'AD1D09';