If a Tree Falls is told in alternating voices, Kirsten and Walk. Walk's chapters tend to be shorter, which is a shame since he's the more interesting (or at least, less annoying) character. Ordinarily this alternating-voice thing wouldn't bother me--but Kirsten's chapters are first-person and Walk's third-person, making it sound like Kirsten has a strange omniscience. The budding friendship between these two was more interesting before the Big Discovery That Changes Everything, the repercussions of which felt rushed and insincere. 
 After Al Capone Does My Shorts, I guess I'd expected something better. This wasn't bad, but it wasn't really great, either--it's just another addition to the long list of mediocre books I've read.