Percy Jackson has another fan

I've been reading the Percy Jackson stories to Sayer and Duncan (when Duncan decides to be interested) for several weeks now. We read a chapter a day before bed. We're in the last third of the third book now. Sayer is enjoying it lots.

And I've noticed that another pair of ears have been paying attention while I read.

Frequently, while I'm in Sayer's bed reading to her, Mark is in Duncan's bed, just a few feet away, reading to him. And when he finishes whatever book he's reading he lays with Duncan, listening to me.

He says the author tells a good tale, though he also notes that it's pretty easy to follow since he'll miss a night or two at a time and have no trouble figuring out what has happened.

He was just in there now, listening to me read. I guess now I have 2 reasons for getting the last book. I wonder when it's due to come out in paperback ...