Who Killed Marcus Brooks? takes place after the events of Mrs Lever is Here. Hayley, Cami, Jessica, Ethan, Brianna, Casey, Missy, Hayley Mitchell and Hayley's cousin, Danielle went to New York for to forget about Lauren. In night sky, Hayley Mitchell found Leon's brother, Marcus Brooks, stab in back and stab in stomach 4 time, fall when somebody push him in root from his house, break his head with lots of blood come out from his head and she find Hayley's wallet in Marcus's coat pocket. Leon and the detective go to find Marcus's killer but somebody kill other people. Hayley think Lauren Malloy is alive but everybody think Lauren is dead, Hayley think Lauren kill Marcus, Will Hayley be right?
- Georgie Henley as Hayley McDonald/Lauren Malloy
- Mark Wahlberg as Detective Leon Brooks
- Natasha Henstridge as Chloe Brooks
- Emma Stone as Danielle McDonald/Hayley and Lauren's cousin
- Isabella Acres as Rosie Brooks
- Caitlin Carmichael as Katie Brooks/Hayley Mitchell
- [[Emma Bell as Cami Watson
- Amber Heard as Jessica Mitchell
- Matthew Knight as Ethan Carsia
- Ellen Wroe as Brianna Albertson
- Julia Stiles as Casey Strode
- Dakota Fanning as Missy Gibson
- Donnie Wahlberg as Marcus Brooks/Leon's brother
- Eric Lively as Ryan Porter
Missy and Hayley had found a red jacket on the ground after Lauren is killed. Missy told Leon if she can keep it. Leon said yes. She put it on. As Missy puts the jacket, a man (Ryan Porter) spots her, Hayley saw a man mistaken her as a woman name Janice Hooper.