|Portrayed By||[[Malik Yoba]]|
|Family||Jeannie Harken (wife)|
Bill has the ability to enhance his strength and speed triggered by a "fight or flight" response. It is implied that he can activate this state at will. Bill cannot stay in this state for very long or else he will become cripplingly fatigued. Bill suffers from anger management. He has what Rosen describes as "boundary issues;" he routinely samples other people's food without asking permission.
Bill meets with another agent outside the Jacob K. Javits Federal Building in New York, New York. The other agent gives Bill some files pertaining to veterans with post-traumatic stress syndrome who have criminal records. In the PILOT Bill Harken talks with his wife Jeannie before leaving home for the day; outside he finds that a large vehicle is blocking his driveway. He exercises his hyperadrenal capability and pushes the offending vehicle sideways out of his way. He is then contacted by Dr. Rosen to investigate a sniping when they find the guy who did it Bill goes after him eventually catching up to him the man is then revealed to be Cameron Hicks who was being mind controlled by The Ghost, they figure where the Ghost is but who then commits suicide but is then revealed to be a fake The Ghost then takes the oppurtunity to brainwash Bill and force him to kill Dr. Rosen but is stopped by Nina. In the season finale Bill along with Gary discover who Stanton is and during some events joins the team on the assault of the red flag base he is then attacked by an alpha who can burn things and dispatches of him and another hyperadrenal, after the battle he suffered some burns but recovers and greets Dr Rosen as ge heads to D.C to tell the world about alphas.
- Bill used to work with the FBI, before an incident where he broke his superior's clavicle. Despite an offer to return to the bureau during Bill and Gary's Excellent Adventure, Bill prefered to stay with the team
- Bill can also enhance the strength in his legs, enabling him to run considerably faster.
- In addition to enhanced strength and speed, he also seems to become invulnerable, and only seems to respond to pain after he stops using his ability.
- Bill seems to be immune to Matthew Hurley's power to make people mad.