Due to the difference in age between Tyler and Dan, more or less fifteen year, you could expect that the one mad would be Dan and Tyler the one always trying to be the balanced one, and instead, in this second novel, we understand that Tyler "needs" Dan, probably as much as Dan needs him. Dan is the anchor to reality, and the reason why Tyler can constantly and firmly refuse to come back in service. And now it arrives another element that adds to the claustrophobic feeling of the story: actually Tyler comes back in service, but all his work is brought on by home, using the internet and his inquisitive mind. Again a claustrophobic feeling, seeing that all the action happens inside Tyler's mind. It's like the outside world doesn't exist, like if they leave their safe haven in the woods, only bad things can happens. The cabin is, at the same time, shelter and prison, and Dan is the first to realize that, if they don't have each other, there is no way he could survive alone there.
Dan is growing in this sequel, he is not yet at his full development as a man, but he is near. You notice that not only from some behavior, like not running away when he is mad, but trying to talk it off, but also in their sexual encounters; more than once Dan takes the lead during sex, and Tyler lets him do so. More, I think that Tyler needs it. When he has too much things swirling in his mind, letting it go, not being the one in control, it's probably the only thing that saves Tyler from going totally nuts.
In a way Dan and Tyler are equal, the difference in age is shortened by their own faults: Dan not yet a man, with still a baggage of insecurities and Tyler with all his nightmares, regrets and fears.
1) Wild Raspberries: http://elisa-rolle.livejournal.com/339025.html
The Rainbow Awards: Third (and last!) Phase: http://elisa-rolle.livejournal.com/85035