Final answer:
Without additional context or information about the story involving Inkling and Ethan, it is not possible to answer the question about what book Inkling was reading in Ethan's backpack.
Step-by-step explanation:
The question pertains to a specific event in a story where a character named Inkling was reading while being in Ethan's backpack.
However, without more context or information about the book or story in question, it is not possible to provide the title of the book that Inkling read.
The excerpt provided by Li Young Li does not contain information about Inkling or Ethan, and it seems to describe a different situation about a boy and his father in a room full of books. Therefore, it is not relevant to answering the question about what book Inkling read.