From The TV IV
Powell's cell is a subset of Marwan's group of terrorist cells. It was headquartered in the Rockland Building in downtown Los Angeles.
- Since Marianne gave the information about Jack and Audrey's trip to a security company to Powell, the terrorists that attacked the company are considered part of Powell's cell. The terrorists in the Rockland building are also obviously part of Powell's cell since that is where he had his office.