Sorry about that, I'll try to explain. I can also go edit it to be less unclear.
Luke, Juiliet, and Mara were the first team to enter the company, implicitly they were ambushed and have been running around since. The dark shape is Mara Mercury, who waited around the elevator area for the doors to open and jumped in when they did, hoping to use it. After Aiden, Ben, Tiberius, and Lost showed up, they all made contact for a short time. When Mara got to work on blowing down the stairway door, thhey split into two groups going two the different directions of the concentric hallway: Aiden, Lost, and Tiberius went one way, Ben, Luke, and Juiliet went the other way.
It is a trap, they were set up.