Second in the Foundation series, Foundation and Empire feels more like a discrete story than the original, which was comprised of numerous shorter works stitched into a larger narrative. Empire is still not a single story, however, but two. The first story, speaking most directly to the book's title, concerns the last gasp of the first Galactic Empire as an ambitious general sets his sights on Terminus, the home planet of the first foundation. The story plays out much like those from the original book, where a wise and level-headed protagonist shepherds through the successful unfolding of Seldon's plan.
It is the second and longer story of the book, The Mule, where things get more interesting, for it is here where the Seldon prophecy appears, finally, to break down. The cause of this breakdown is the eponymous Mule, an enigmatic warlord with mutant powers to great and specific to be detected by the broader sweep of Seldon's psycho psychohistory. The story thus plays out more like a mystery, as hidden forces pull at the husband and wife protagonists, dragging them into the maelstrom of galactic conquest and goading them to seek Foundation's salvation from its would-be conqueror.
The prose remains vintage Asimov, though feels a bit more refined than that of the first book, perhaps because the stories themselves were more comprehensively planned. As always, it’s the ideas themselves that sparkle, the words and characters serving mainly as vessels.