Brooke Hammell is not a name we hear right away, the lady preferring to go by Casper, as in the friendly ghost, presumably. She's one of the passengers on Flight 234 from San Francisco to Seattle in "Rewind", but she matters because she's the one Chance and Winston have been hired to protect, without knowing her identity.
When the plane develops all kinds of engine and electrical trouble, the computer whizkid is able to step in and help level things off with her laptop, although it does reveal her identity to several people. One of them is Laura, the assassin hired to ensure 'Casper' never sees Seattle, and only some quick thinking and legerdemain on Chance's part keep Brooke breathing. She makes it to her rendezvous, and seems to have helped the company make the Internet safer again. At least, the alleged black hole in the architecture of online communication isn't brought up again.
She's played by Ali Liebert.