question: What's the number of the episode seen by 2.99 millions of people in the US, where performer 2 was Heather Anne Campbell?
answer: SELECT MIN(_number) FROM table_23294081_11 WHERE performer_2 = "Heather Anne Campbell" AND us_viewers__millions_ = "2.99"
context: CREATE TABLE table_23294081_11 (_number INTEGER, performer_2 VARCHAR, us_viewers__millions_ VARCHAR)