24 Season 4 finale to “change the show forever”

Question: C’mon, man. Last week there was very little information on Lost, 24 or The O.C. In fact, nothing. Can’t you give us some spoilers or something? — Sean
Ausiello: Here’s some scoop, er, buzz on 24: As Mary Lynn Rajskub hinted to AA last month, Chloe will go out into the field in Episode 19 and be forced to use a gun for the first time. And something will happen in the season finale that my 24 mole says “will change the show forever.” Short of whacking Jack, I’m not sure what they could do to top blowing up the president of the United States. But I can’t wait to find out!

Source TV Guide