After Griffin runs out of Kemp's house, the narrator (and everyone else) loses track of him for a day: "No one knows where he went nor what he did" (26.1). So a lot of this chapter is speculation (meaning guess-work).
The narrator also has a brief moment of sympathy for Griffin. After all, Griffin was betrayed by a friend.
But no one else is going to be nice to Griffin: everyone else seems to be out hunting him with guns and dogs. To make things worse, Kemp spreads the news that people need to keep the Invisible Man from eating or sleeping.
Unfortunately, that doesn't keep Griffin from killing an old man named Wicksteed. Since no one was there but Griffin (and Wicksteed, we guess), we'll never know what happened, only that Wicksteed was beaten to death with an iron rod. This is getting intense.
Although there were no witnesses, some men around there heard a voice "wailing and laughing, sobbing and groaning" (26.11). The narrator thinks that maybe Griffin was upset after killing Wicksteed (of course, not as upset as Wicksteed probably was about being killed).
Griffin has trouble finding shelter. All the houses are locked and everyone is on guard against him. What's worse is that everyone seems to know the secrets he told to Kemp. Some friend he was.
Sometime in that day, Griffin found the time to rest and eat, since the next day he was "himself again, active, powerful, angry, and malignant, prepared for his last great struggle against the world" (26.12). One Invisible Man versus the world – we wonder who will win.