Who wrote the episode with 9.81 million US viewers?
CREATE TABLE table_28688313_1 (
    written_by VARCHAR,
    us_viewers__in_millions_ VARCHAR
)
SELECT written_by FROM table_28688313_1 WHERE us_viewers__in_millions_ = "9.81"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Who wrote the episode with 9.81 million US viewers? ### Input: CREATE TABLE table_28688313_1 (
    written_by VARCHAR,
    us_viewers__in_millions_ VARCHAR
) ### Response: SELECT written_by FROM table_28688313_1 WHERE us_viewers__in_millions_ = "9.81"