FBI Special Agent, she investigates the Gibson Lane murders with her partner Nicky Gallo. As they question Ellison Lane - Gibson's brother - about what he saw in prison when PH34R killed Gibson in front of him, lawyer Sydney Brant paid by Gabriel Winter will interrupt them and ask for the questioning to be postponed.

Brant will leave with Ellison and place him in a car that will take him to Gabriel Winter. Siobhan and Nicky learned that Gabriel Winter had rented a hotel and will go there. When getting out of the car, Nicky will be surprised by PH34R, who will kill him by slitting his throat. Siobhan tried to defend him but PH34R will shoot her in the shoulder before walking away. She will be rescued later, lying in the parking lot, by Darren and Yoshi. She asked for reinforcements from her boss, Madeleine Snow, but got a negative response because of the many serial killings taking place in the territory.