Hobbes and Darien investigate a hacker trying to break into the Agency computer system. The hacker escapes, and Eberts manages to suggest being allowed to tag along with the team as a computer expert. He and Fawkes sneak into a internet cafe but are ambushed. Knocked out from behind, Eberts is taken back to the Agency and soon starts to act increasingly aggressive, going so far as to ignore the Official when inevitably told to "Shut up, Eberts!". Eventually Hobbes and Fawkes discover that Ebert has been replaced by their invisible nemesis Arnaud DeFehrn. DeFehrn gained cell samples of Eberts during his last physical, and used them to make up a lifelike skin mask. He needs Eberts' access to get into the Official's computer. After a bicycle & skateboard chase, DeFehrn manages to elude Darien, leaving the Agency to wonder when DeFehrn will show up again.