user: Question: What episode number of the season was written by Tom Garrigus and had 2.31 million u.s. viewers?
Columns: ['Series #', 'Season #', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code', 'U.S. viewers (million)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [37.0, 1.0, '"Yankee Dan"', 'Emile Levisetti', 'Dailyn Rodriguez', 'May27,2013', 'BDF401', '3.26']
SQL:

assistant: SELECT "Season #" FROM "Table" WHERE "U.S. viewers (million)" = '2.31' AND "Written by" = 'Tom Garrigus';