Okay so I got a few PM's asking what happen to Anna so basically pitch erased her memory and sent her to a new world. But since jack doesn't know that so he's gonna go after Pitch. BUT what pitch doesn't know is that Jack happens to be friends with Hiro and the gang so- I'm gonna spoiler the whole story! Okay I'm shutting up there's your explanation bye now :) oh and Anna now looks like the picture above
