Cate is shocked to discover that Principal Gibb (Adam Arkin, ""Chicago Hope"") has hired C.J. to be a substitute teacher at the high school. But when C.J. catches Rory cheating on a test, he is torn about reporting it when Cate tries to persuade him to look the other way. Meanwhile, when Bridget breaks her leg because of Kerry's blunder, she makes her little sister's life a living nightmare.