The Hannibal franchise features a rich universe that’s full of uniquely disturbing characters, but Will Graham and his fate are particularly chilling and the novel canon fills in some blanks post-Hannibal.
Most people’s introduction to the brilliant and sadistic Dr. Hannibal Lecter comes from Jonathan Demme’s 1991 film adaptation of The Silence of the Lambs. That chapter from Hannibal’s story centers around Clarice Starling, but as fascinating as she is as a protagonist, the Hannibal television show reiterates why Will Graham is just as important of a foil for the cannibal killer.
Thomas Harris wrote four Hannibal novels, but Will Graham only appears in the first book, Red Dragon. Bryan Fuller’s sublime adaptation of the Hannibal story remixes the events in a way that makes Will Graham the focus, and uses the character’s fractured mental state as the unnerving point of view for the television series. Fuller’s series and Harris’ novels ultimately go in different directions, but there’s still lots of overlap between the two. In fact, Harris’ novels provide several hints to what’s happened to Will Graham even after he exits the story.
Both the conclusion of Red Dragon and Fuller's Hannibal TV series involve Will Graham facing off against Francis Dolarhyde, the Tooth Fairy killer. The television series has Will fight alongside with Hannibal as they take out Dolarhyde together, but in the Red Dragon novel, Will is taken by surprise. Will and his family survive the attack, but he gets stabbed in the face and suffers some ghastly scarring. This is the final straw for Will Graham and, rather than get further drawn into criminology or Hannibal's many allures, he instead retreats to a depressing life in Florida with his family.
Will Graham is obliquely referenced in Silence of the Lambs when it's revealed that he's fallen on harsh times and become a disfigured alcoholic. Much like before, the stress of Will's cases has infected him and left him on shaky ground. He's referred to as being unstable, so it's unlikely he'll even return to the field. Will's fate is a bleak, albeit realistic one, and the scars on his face that he's forced to look at every day are an unfortunate reminder of how deeply he threw himself into his career.
It’s also worth nothing that during the recent Hannibal Zoom reunion, Bryan Fuller spoke to what both Hannibal and Will are likely up to since the events of the season 3 finale. Fuller explains that Will is probably still on the run with Hannibal, yet they’ve fostered a bond together. Fuller speaks to how Will’s mental state would be frayed through all of this, and any kind of relationship between Will and Hannibal wouldn’t be possible until a hypothetical season 5. It appears that Will Graham’s mind will be a mess in whatever series of events are followed, but only in the Hannibal book canon is he physically scarred as well.