Peak's struggles with his past, especially letting another climber pass him in Peak and the precarious relationship he has with his father, add a layer of emotional depth that will appeal to slightly older readers. His sweet off-and-on romance with Alessia, as well as their support of one another through difficult times, is also a nice touch.
The different groups that the climbers run into are interesting as well, from corrupt Burmese soldiers who take bribes as a matter of course to Chin, whose help ends up being invaluable, to old friends from the past who show up for mysterious reasons. In some ways, it's unlikely that Peak would run into so many of them, but some, like the father of one of the PEACE climb members who died, add a nice sense of closure and make for a very rich story.
The first Peak Marcello adventure, Peak, came out in 2007 and has been a huge hit every year with my readers. I'm going to need to buy yet another copy because it is worn out. With this third book, Peak's adventures have become a series that readers who love Gilman's The Devil's Breath and Pam Wither's books about extreme sports will go through at a pace fast enough to outrun an avalanche!