Shortly after Sol hatches, his parents and nestmates discover the young crow is a gifted "thinker-linker" able to communicate with distant birds, with the souls of dead birds - and even with humans! As Sol masters flight and makes his first migration, he learns many members of the Great Flock - birds all over the world - are suffering from terrible catastrophes. Fewer insects, murdered forests, even the lack of krill in the oceans: these are all caused...