The mystery man isn’t talking. Beckett receives a call from the Attorney General ordering her to release her person of interest. No problem. She just needs some information in return. The mystery man is Stack. He’s a special investigator for the Attorney General’s office. He’s there to objectively look into Tanner’s death. He says the drone didn’t come from Fort Drummond, but it did belong to the U.S. Someone hacked into it to blow up Dale Tanner’s car. Castle believes this could be the rise of the machines. Beckett uses his theory to her advantage as she scares him with a remote control toy attack in bed.
Stack believes that a man named Simon Warburg is the only one who could have hacked the drone. The guy believes that drones will be used to attack U.S. citizens someday. Perhaps he was trying to prove this by killing an activist like Dale Tanner. Castle and Beckett track down Warburg by locating the bookstore where he shopped. There’s a copy of Storm Season in the shop… on the clearance table. Castle’s crushed. As for the case, the bookstore owner points them toward Warburg’s location. It’s in an open field area where a small plane heads toward Castle and Beckett. It’s coming in for an all-out aerial assault.
BANG! BANG! BANG! The plane fires on Castle and Beckett, so they fire back. CRASH! There’s some debate as to who takes down the plane. Warburg doesn’t care about that. He’s just ticked someone shot down his drone (which was firing blanks, by the way). Warburg admits that his technology is what got Tanner killed. He knows that the next generation of drones won’t have pilots. That means they’ll kill without conscience or reasoning. He wants Dale Tanner to post his drone-hacking software to his website. That wasn’t a great idea, as anyone with a computer could then take over a drone. Someone close to Tanner swiped the information though.