Final answer:
Henry is afraid of the possibility that Keiko has died.
Step-by-step explanation:
Henry is afraid of the possibility that Keiko has died. In the given excerpt, it is mentioned that Henry is getting afraid of John and that he seems queer sometimes. This suggests that Henry's fear is related to John's actions, which are likely connected to Keiko's well-being. Additionally, it is mentioned that Henry and Jennie have caught John looking at the paper, indicating that there is something distressing about its contents. Therefore, the most likely possibility that Henry is afraid of is Keiko's death.