* He works for a large corporation: This is implied when Brian's father mentions the company's secret project, which is why he cannot tell Brian more about his work.
* He is a secretive and mysterious figure: Brian's father's job is heavily veiled, and he's portrayed as a distant and somewhat aloof figure.
* His work is important: The fact that Brian's father feels compelled to hide his work, even from his own son, suggests it's important and possibly sensitive.
Based on these clues, we can speculate that Brian's father might be involved in some sort of:
* High-level government work: Perhaps a researcher or engineer for a defense contractor or a similar agency.
* Top-secret scientific research: He could be working on a project with national security implications.
* Corporate espionage: The "secret project" could be something related to corporate secrets or competitive advantages.
However, without more concrete information, it's impossible to know for sure what Brian's father does. The mystery of his job adds to the overall theme of survival and self-discovery in the book.