What did Enzo know but was unable to communicate to others?

Enzo, the dog and narrator of the story, possesses a deep understanding of human emotions and circumstances, despite being unable to communicate verbally in a way that humans can comprehend. His insights come from his keen observations and his experiences as a companion to Denny and his family.

The knowledge about Eve's illness is significant because it not only affects the family dynamics but also deeply impacts Denny's life and responsibilities. Enzo recognizes Eve's struggle and how it affects the emotional landscape of the household. This aspect of Enzo's character highlights the themes of loyalty, love, and the innate bond between pets and their owners. His inability to convey this understanding emphasizes the poignant limitations of being a non-verbal observer in a human-centric world, adding depth to the narrative as he wishes he could express his concern for Eve's health and the implications it has for everyone involved.

In contrast, while Enzo may observe Denny's stress, Zoë's feelings about missing her mother, or any flaws in the twins' reliability, his awareness of Eve’s sickness stands out as a critical point of concern that directly affects the family's well-being and highlights the emotional depth of the story.