Core [1]
When the elevator stopped on the 90th floor, Zara seamlessly attached her shadow to the researchers so they could enter the facility uninhibited.
Zara's shadow worked similarly to a subspace in that it could both hold living beings and was concealed from most people's perception. This subspace used shadows as a base and like such could latch to shadows and be carried by them.
In such a dimly lit area like the underground bunker, Zara's ability was extremely useful.
And so, Damien and Zara were carried by the researcher as she walked through the facility. Similar to the 60th floor, there were hundreds of different researchers at their workstations handling separate matters. The difference was the subject of experimentation.