Antimony Carver has just transferred to Gunnerkrigg Court, a strange school the size of a city, and which looks more like a large industrial complex. And she's mysteriously acquired a second shadow. She manages to communicate with it, and learns it comes from the forest on the other side of the river, separated from the Court by a deep gorge. The sole bridge to the forest is lined with lights so there aren't any shadows on it, so he can't go home. Annie can't cross herself because she'd get in trouble, so she finds a dismantled robot in a room with "NO Spare Robot Parts" and snaps him back together. She sends the robot, who she calls "Robot", across the bridge to take Shadow 2 home.
- Early Installment Weirdness: Annie putting Robot together implies she's quite competent with technology, when it's later established that she isn't, and it's her best friend Kat who's the Gadgeteer Genius. It was Retconned that the dismantled Robot was just snapped together, and he was easy to turn on because all Seraphs have large red on/off buttons on their heads.
- Giver of Lame Names: Annie dubs the living shadow who starts tagging along with her "Shadow 2", and the robot she rebuilds "Robot". These names stick.
- Living Shadow: Shadow 2, of course. He starts tagging along with Annie.
- The Noun and the Noun: "The Shadow and the Robot".
- Sequel Hook: Robot decides to stay in Gillitie Wood to look for a new arm.
- Suspiciously Specific Denial: Starting a theme with robots being bad at deception, the room where Annie finds the dismantled Robot has a sign on the door proclaiming "NO Spare Robot Parts".