Derek and Jason interrogate the guy about his boss. Seems Torres started acting weird after he returned from a trip to the Philippines. At first, he wanted all the lights on in the place, and then he got really sad, and then he smashed all the lights out because he preferred the darkness. Derek asks if there are any records of what Torres bought on his last trip, or whom he met with. The guy says that the tape that was playing is the record, so Derek snags it.
Chloe is in a library somewhere, looking at a picture in a book that resembles the tentacle-shadow thing that happened to Sam with the dog. Her phone rings. It's Derek, explaining about what happened to Torres. Chloe doesn't want to talk to him, and hangs up. Jason asks what they do now, and Derek says, "I got to do what I got to do!"
Cut to Sam's house, where Sam, Jennifer, and Dr. Gibson appear ready to go out somewhere. Chloe knocks on the door and begs for a chance to give her explanation. Dr. Gibson doesn't want to hear it, but Jennifer gives Chloe thirty seconds. Chloe launches into an explanation of the "mythical precedent" for Sam's problems -- cultures that believed that a "light-stealer" lives in their shadows. Dr. Gibson has heard enough, and claims she'll be filing charges against Chloe with the board in the morning. Meanwhile, she's taking Sam to the hospital for the tests. Dr. Gibson drags Sam out to the car. Chloe follows, begging Dr. Gibson to listen to her. Sam yells out for Chloe, and explains that "it" is going to get "her." Derek's truck pulls up, and the shadow-tendrils start to climb up Dr. Gibson's body. She appears to be choking, and no one can get into the locked car. Derek busts the passenger window with his elbow. The shadow-tendrils recede, leaving Dr. Gibson (ew!) foaming at the mouth. Derek grabs Sam from the car, and we see the shadow-tendrils crawl back into Sam's shadow. Derek yells Sam's name about a hundred times, but Sam is unresponsive.
Cheap gag ahead. A man and woman approach a desk in a hospital, where the woman asks for help for her boyfriend, who has had too much to drink. An impassive nurse says that this is pediatrics, and directs them to admissions. The man leans forward and vomits all over the desk. Why? No reason. At least that we know of. As he vomits, Chloe walks hurriedly past. She meets up with Derek outside a hospital room. They look in on Sam and Jennifer, both asleep. Chloe says that the doctors think Dr. Gibson had a "bad seizure" and the next twelve hours are critical. Chloe apologizes to Derek for not understanding that this is more than a freakylink to him, but she wonders why it is. Derek says that he believed Sam when he was scared, because Derek was scared of the dark too, and by the time anyone believed him it was too late. Chloe asks, "Too late for what?" Derek responds, "To turn on the light." Oh, for crying out loud. I was starting to like this episode and then they have to start with the wooden dialogue.