William B. "Will" Baxter is a young man living in the overgrown ruins of a town near Gearnus City with his wife Martha, who is suffering from the Desperation Disease. In World's End Garden, William finds Renton collapsed from dehydration, who takes him to his cottage to recover. There, he reveals that he is attempting to rebuild his life in the remains of the town in which he was born by planting crops and pulling out the Pile Bunkers with a strange ritual. Will explains to Renton that all of mankind's attempts to live beyond their means, that is to say, to use more energy than is provided them by the sun, is the source of all their misfortune and that simple living and love are all that people truly need.
Will reveals that he was a former member of the state military who encountered Martha during a raid and rescued her, fleeing the military in the process. Promising to take Martha to his birthplace, he traveled with her a great distance, falling more and more in love with her as time went on. But when they finally arrived, they found that the town had been devoured by Scub Coral and destroyed by Pile Bunkers, the sight of which drove Martha into the psychological collapse of Desperation Disease.
It can be assessed that William's devotion to his wife Martha despite her vegetative state serves as an example to Renton and his feelings for Eureka. Renton assumed Will was unaware that Martha suffered from the Desperation Disease and tried to tell him but Will responded that Martha understands what he says. He furthermore tells Renton that the loved ones of the victims suffer more than those infected. At the time, Renton was confused of his purpose in life and how his presence and feelings for Eureka affected her. Will was the one who taught Renton the facts of nature and love; to really love and be with someone, he needs to keep his word and face the hardships in front of him. When Will asked Renton if there was someone he wanted to be with if the world ever came to an end, Renton immediately realized he wanted to reconcile with Eureka no matter what she thought of him and began to mature more.
After Dewey launches his plan to destroy the Scub Coral with Oratorio Number 8, the impact of the attack causes fragments of the Scub Coral to destroy towers across the planet and send debris flying. The debris begins falling across the planet, with William watching the falling debris fly overhead his farm and turns to see Martha fully conscious due to the Command Cluster being destroyed, standing and smiling at him as his farm is engulfed in an explosion from the debris, killing them both.