Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_28019988_5 (season__number INTEGER, us_viewers__million_ VARCHAR, written_by VARCHAR)
### Question:
What episode number of the season was written by Tom Garrigus and had 2.31 million u.s. viewers?
### Answer:
SELECT MAX(season__number) FROM table_28019988_5 WHERE us_viewers__million_ = "2.31" AND written_by = "Tom Garrigus"