Cassie was in the area of the Sensoriums herself. She was trying to train her Kythian mole grub, Pinky, and it worked better if Stacy was providing the treats rather than using her own food stores- or the slop. Then she heard someone walk by, when she poked her head out she saw her friend.

"Hey!"

Yeah, totally clueless as to anything going on here. At least for now.