‘Ant-Man and the Wasp’ Interview: Hannah John-Kamen’s Ghost is One of Marvel’s Best-Kept Secrets Hannah John-Kamen played Ben Mendelsohn’s number two baddie earlier this year in Ready Player One, but she’s graduating from henchwoman to supervillain in Marvel Studios’ Ant-Man and the Wasp. The British actress plays Ghost, a character who…well, who we don’t really know much about at this point.