Like Sarah here, stalking through this empty house. There's no furniture in the house. There's also no sign of Walsh, but she notes that, curiously, the chain on the front door is on, which means that he didn't go out the front door, anyway. On the rug near a shelving units are curved tracks. Sarah checks the shelf, which sure enough pulls away from the wall, revealing a hidden doorway atop a set of descending stairs. She makes her way down, gun ready.
In a dim basement is a table with several computer monitors, with split screens displaying dozens of camera angles of security footage. She taps a couple of keys and finds it really easy to switch between angles. Then she spots a smear of fresh blood on the floor, and she heads out into the hall. We pan back over to the monitors and we can see, on one of them, John searching a bedroom.
He's rifling through drawers, looking furtively around, but gets caught by Zoe anyway who wants to know what he's doing in her parents' bedroom. So maybe a better idea would have been to have Derek or Cameron search the room while John stands guard, hey? Or is Derek still too busy cramming shrimp down his throat? "Your father's alive, isn't he?" he says. She tells him to "get out," and runs off down the stairs, so he chases her and tells her he knows that she's scared, but he can help. "No, you can't!" she says, and points upward. Derek looks up, and sees a camera hidden in a ceiling grate. You know, if you're going to POINT at the camera, you might as well just say "There's a camera up there!" since the camera can, you know, pick up you POINTING just as well.
Sarah's still strolling through the underground tunnel, which is quite reminiscent of the tunnels populated by the human resistance in the future. Eventually she comes to a ladder leading up to a door in the ceiling. Up she climbs and opens the door a crack and looks outside. It seems to lead to a garage.
At the wake, Derek answers his cellphone. It's Sarah, and the two of them do their little beepy code thing, and she tells him she's in a garage but "it's a long story" and he says he's at a "fake wake," and then she looks out the window and hangs up her phone. She walks over to the window and raps on the glass, because Derek is out there. Of course, so is everyone else at the wake, so it's a good thing she used her extra-special tapping that only Derek could hear and react to.