Your dad is reading Extremely Loud and Incredibly Close by Jonathan Safran Foer. He also wrote Everything Is Illuminated. Your mom and dad love that movie. Extremely Loud and Incredibly Close is the kind of novel that is so exquisitely crafted as to call into question its very origins. This isn't so much the crafstmanship of one author as it is the divining of an entire nation's rent and broken heart.
A boy finds a key in an envelope, but he doesn't know what lock it opens. He sets off on a mission to find out. But across the whole of New York City, where the boy lives, there are 161,999,999 locks that the key won't open. Still he opens more doors to a box-of-chocolates variety of people than the key itself ever could.
Your mom insists that your dad finishes reading the books he buys. He doesn't always do that. But if the book has an autistic (or autistic-like) child as the protagonist, then your mom's insistence turns into something closer to bullying. No matter what other unread books sit on the shelf, your dad has to finish those in particular. He has to.
Your dad finished reading the Coming of Conan the Cimerrian last night. And while Conan's stories are adult fantasy fiction as envisioned by an overgrown and surprisingly poetic twelve-year-old, otherwise known as Robert E. Howard, that decidedly does not count as a book with an autistic (or autistic-like) child as the protagonist.