In setting out to read the Skylark series I took it upon myself to read all four books. While I have read and enjoyed the first two books many times over the years and have fond memories of the third (though I had only read it once), I remember that the fourth book had struck me as being very badly written the one time I read it, more than forty years ago. Reviewing the series for my latest reading I was quite surprised to learn that it had been nominated for the 1966 Hugo Award. Was it really as bad as I remembered?
After rereading it I think the answer is - yes.
The book has a number of flaws. The chief among them is it is what might be called a "do-over sequel", where an author having told a story and brought it to satisfying to conclusion, immediately undoes that solution in the sequel so as to have the story to do over again. This happens multiple times in this book. First DuQuesne, Seaton's arch enemy from the previous books who was captured and sent on a one way trip to the end of the universe at the end of previous book, is released from that fate by way of a rookie mistake and sets about trying to get his revenge on Seaton - only to fail at this himself due to a frankly not very credible mistake. Evil races who had been the baddies in previous books and been destroyed turn out not to have been destroyed after all and have to be dealt with all over again, and (as in previous books) Seaton and friends, lacking the technologies they need to deal with their problems have to search the universe for races which have the technologies they need. Do-overs occur within the book, such as when DuQuesne runs into something he can't handle and appeals to Seaton for help; he is accepted back into the fold, betrays him, and then calls for help again and is forgiven again when he runs into something else he can't handle. And of course, the threats are bigger, the countermeasures are bigger, and the stakes are supposed to bigger too, except that I really found it hard to care by the time I got to the end. Nor did DuQuesne's love interest (who went, I kid you not, by the name of "Hunkie") help matters.
I am really at a loss as to how the book could have been nominated for a Hugo. I can only put it down to nostalgia on the part of those voting, harking back to Smith's earlier, better stories.