So anyway, the taxi arrives at its destination on a dark street in a rundown area with a lot of dark, empty buildings. And, like, no traffic, so it ought to be completely obvious that they're following the cab. And Olivia tells Peter to stay in the car, and he says, "There's no way you're going in there alone!" and then she asks him nicely and he agrees to sit on his ass for the duration, as long as she calls for backup. Olivia says Harass wants her to screw it up, so if she calls for help, he'll do "whatever it takes" to make her look bad.
Speaking of Harass, he's now noticed that Luke is not there anymore, and he goes stomping into the bullpen to ask where "Dunham and the kid" are, like Olivia and Luke are a pair of Old West bandits. And he asks one suit who we've never seen before, who doesn't know, and then rather than just asking Charlie or Broyles, Harass orders someone to trace the GPS on Dunham's car.
Olivia's stalking through the warehouse, gun raised, and we can hear muffled arguing between Luke and his dad. "You actually killed Greg from here?" says a distraught Luke, and Dempsey says, "All they had to do was give me a chance! A fair shake! A chance to prove myself!"
Olivia draws closer, while Luke cries about how he used to look up to his dad, but now he's pathetic, and before Dempsey can respond, his Someone's Been In The Building For Several Minutes alarm goes off, and he's got three monitors that all show the same camera picture of Olivia looking around. Yeah, you need your security cameras to have triple coverage. Dempsey tells Luke to go: "They're coming for me, not you." Luke protests and then stomps off.
Olivia goes through a door, and we see Dempsey's cot setup, and she sweeps her flashlight around the room, and we can see Dempsey's bank of computers, but there's no Dempsey. She looks around at all the computers and monitors, and over at the mini-fridge and bachelor's mess all over the place -- this looks like the dorm room of the guy who lived next door to me in college.