Nothing really happens. There is an attempt at world building but its more of an anthropological exploration of Elves which doesn't contribute to the plot line. 
 Eragon starts taking lessons from Elves. His cousin is leading an army elsewhere and in the end they both meet at the same battle ground fighting the same enemy. 
 It's a lot slower than first book and there are couple of things which stand out as plain weird. Eragon gets help from Elves because of him becoming a Rider and the blessing involves physical improvements. He is very happy that his scar is gone and is now beautiful. 
 The timeline of the novel is very confusing. I gave up trying to figure out by mid of the novel as things never added up and as there were more characters than before, it wasn't worth the effort.