Book forty-six: Harry Potter and the Half-Blood Prince by J. K. Rowling

Truth be told, Darren finished the last couple of chapters with Hen whilst I was trekking with gorillas* in Africa but since I did the majority of the reading, I'm including this in my count.

Henry is an attentive listener. Darren said he was "legit scared" when they read the chapter where they [Dumbledore and Harry] cross the underground lake to get the horcrux. But he is enjoying the stories and is invested in the people. We're taking a small break and working our way a couple of books before we start the seventh and final book of the series. 

46 down plus 6 to go.