Why did House fire 13?!?

I didn't watch the whole 9th episode but I found out that he is firing her (13) ... any ideas why did he do that and is there a chance for the old guys to come back? (I mean Chase and Cameron)

I don't think you watch the whole episode thoroughly. He did fire 13 (actually her real name is Remy Hadley), because he did not have room enough for another team member. But if you did see the part where Cuddy comes to talk House about not having a woman on his team, House tricked Cuddy into having a 4th team member which was his plan all along. So now 13 will actually be on his staff. I'm so happy House tricked Cuddy, genius!

I don't think that Cameron & Chase will actually come back to his team. House did fire Chase, & Cameron did resign. I do like House's new team & the changes the show made. I hope they keep it that way for now.

I think the old guys do come back at some point but not for long term. I dont know about number 13 as I am in the UK and iit doesnt start here till Feb.