He was acknowledged as a good man with an excellent talent for psychiatry and analysis. But, his inability to adjust to the status quo of investigating crimes has resulted in him losing his FBI job, and he then worked in a mundane job with the homicide departement of the Old City Police Department.
After being recruited by Dr. Magnus in her work at the Sanctuary, Will discovers a new and strange world that is both unbelievable yet completely plausible to him. While his ideas have put him ahead of his time, he finds the world of "abnormals" to be fantastical in a way he can ultimately understand.
Although Will was less than comfortable at first, he has proven himself invaluable in gaining the confidence of his first patient, an abnormal child. This only serves to prove that Magnus was right about his instinct and genuine thirst to know the truth. And she knows that he will prove invaluable to the Sanctuary. He has also totally proven himself to Ashley Magnus after helping to rescue her from what could have been her death.
His choice to stay at the Sanctuary is made after a conversation with Dr. Magnus when she reveals her deepest secrets to him. He asks this of Magnus because of the fact that he has been thrust into a world that he repressed as a child. When Will was younger, his mother was killed by an abnormal which made his life all the more difficult. No one would believe him so he told himself that he was just seeing things and threw himself into studying the human mind and how we can mistake illusion for reality. When Will finds out that what he was seeing was not in fact an illusion and that his mother was killed by an abnormal he begins to research in the Sanctuary's library. His willingness to learn and his need to know the truth prove to be important factors in Magnus's choice in Will as her protegé and prove to be helpful to everyone in the Sanctuary.
- Helen Magnus
- Magnus saved Will's life when he was attacked by an abnormal as a young boy. Unable to save his mother, she secretly watched over him well into his adulthood, and eventually recruited him as her protegé and could-be replacement should anything happen to her. They greatly respect each other, and Will relies on her as a mentor as much as she relies on him as her second-in-command.
- Will was in a relationship with her for several years, but they broke up just prior to his introduction to Magnus and the Sanctuary. Meg seemed to still have feelings for him, but found it impossible to live with him any longer.
- Clara Griffin
- Will and Clara share a kiss not long after meeting during the crisis surrounding the Cabal's Lazarus virus. They have a long-distance relationship for some time, with him staying in Old City and her living in the UK Sanctuary. When the facility comes under attack by the Cabal's superabnormals, Will asks Clara to evacuate with the other residents, but she refuses to go, and is killed in the fighting.
- Abby Corigan
- Will and Abby first met during a course at the FBI academy in Quantico, but she did not leave much of an impression, as he could not remember her when she came to see him at the Sanctuary in 2010. However, at that point, they were immediately attracted to each other, and ended up going on a date shortly after solving the case Abby came to discuss. This proved difficult, as they got into trouble with abnormals on both of their first dates. As of now, the two are in a happy relationship.
Will serves as one of the main protagonists of the series, initially being as unfamiliar with the world of Sanctuary as the viewer.
Although he is commonly called Will, his full first name is shown to be William on his file in the opening credits. Several characters, like Watson and Kate, also call him William on occasion.
In The Depths, Will displays somewhat severe claustrophobia.