Patch does not return to the car. Nora, however, receives a phone call from Elliot who says he can see her sitting in the car. Creep.
Nora enters the school, hoping Patch is somewhere inside with a plan. It's totally dark inside because someone has turned the electricity off.
Nora trips over Jules's dead body. Whoa.
She makes her way to the library, some of the lights flicker back on, and she sees Elliot's body. He is almost dead.
As she takes the scene in, someone pushes her from behind. It's the guy in the ski mask. We finally get the big reveal, and it turns out, the guy is Jules.
Wait a second… isn't he dead?
Apparently Jules used a mind trick to make Nora think he was dead. Sneaky.
Their scuffle leads them to the biology lab, where Jules reveals that he's bribed Elliot for his loyalty (which Elliot proved by killing Kjirsten), has been using Nora to toy with Patch's feelings, and is actually Patch's Nephil vassal—which means Jules is Chauncey.
Jules is pretty miffed about being the vassal and having to give his body over to Patch every year. Seeing that Patch had developed feelings for Nora, Jules planned to torture Patch emotionally by killing her.
Jules has tried several times to kill Nora to no avail. Examples include trying to lure her on the camping trip and shooting the bag woman whom he mistook for Nora because she was wearing Nora's coat.
Jules says he cannot die because Nephilim are immortal, but Nora is able to fight him off well enough to escape the bio lab.