Kat's Crew are three 14 year-old singers and dancers.
Gustavo has been working with them and intend to produce them. This makes the boys jealous, especially because the girls get a poster on a wall and also get to sing the boys' new song "I Know You Know".
In the end, Big Time Rush try to convince Kat's Crew to stay after admitting they were wrong. Kat's Crew accept with one condition if BTR sings I Know You Know which BTR agreed but with one condition:if Kat's Crew does the rap.
Both bands come together and sing their new song I Know You Know as a duet and make the music video by combining the idea from Carlos (using a space theme) and Kat (using an exploding alley theme).
- Gustavo calls BTR dogs, they are the opposite of Kat's Crew because they are called Cats.
- Kat's Crew can also dance and rap.