Isaac is pretty shook at this point, since he's supposed to be on a mission, while the other two aren't really caring. So he takes the cool tech glasses, and scans the crowd using the facial recognition feature. Only one small image locks in, and the person it scans immediately vanishes through a black, camouflaged door on the other side of the club.
But with this lead, Isaac weaves through the crowd (uncomfortably and awkwardly, of course). He's pretty much hit by the sensory overload of loud music, people shouting, dancing, and passing around drinks. Eventually, he gets to the door.
The door leads to a narrow, dimly lit passageway. He can barely make out brightly coloured graffiti art on the walls. The floor is dirty and the area smells musty and damp.
He hears voices down the hall though, so he heads there. There are a couple rooms , most are filled with records or stacks of bottled drinks for the bar upstairs. One is slightly ajar, a muted light coming from inside. He peers in, spotting the girl with her back turned, setting something up on a screen.
Taking the opportunity, Isaac slips into the room, ducking behind piles of empty crates. He can't see the girl, but he could listen in, perhaps.