Casting bites for your Thursday:

I Am Number Four has got its Number Six. THR's Heat Vision reports that Teresa Palmer (Bedtime Stories) will play the sixth of nine aliens who escape their home planet before it's destroyed by a rival species, and then head to Earth and hide as high school students. (What is it with otherworldly creatures and high school? Do they know something we don't? Or, are they just that masochistic?) Alongside Palmer, there's Alex Pettyfer (Beastly) as Number Four, and Sharlto Copley as Four's guardian/mentor.

As one heads to outer space, Dwayne Johnson is getting back to the action, in one fairly surprising casting twist. The Wrap reports that he's going to star in the action-thriller Protection, replacing Clive Owen. But this isn't the first wild casting twist. First it was brewing with Simon West directing Paul Walker, then it was Owen with Patrick Alessandrin (who has also exited). The flick follows a disgraced former Special Forces dude who takes on a Mexican cartel to rescue a judge's daughter, who is supposed to testify against one of the cartel's members after her dad is murdered. Something about cartels is fishy biz in Hollywood these days. After all these star changes, and on the wake of Cartel getting axed, will this go anywhere?

Finally, Variety reports that Emma Roberts and Freddie Highmore are starring in a new teen romance called Homework. Alongside the likes of Alicia Silverstone, Elizabeth Reaser, Blair Underwood, Michael Angarano, Sam Robards, and Rita Wilson, they will play a homework hater (Highmore) and the object of his affection (Roberts). Good luck, Freddie.