I felt decidedly mixed about this one. This is the eleventh book in the Mary Russell series, which gives Sherlock Holmes a romantic and professional partner--and it works. Well, almost always. The series truly is a favorite of mine and usually hits the spot with its mix of Sherlock Holmes pastiche, mystery, and early 20th century historical fiction. I've grown to love Mary as a character in her own right. This one though, takes an entirely different tone than usual--in fact the first half plays as farce. It annoyed and bored me for a lot of that first half, and I considered abandoning it--at least until it regained the promise of it's subtitle: "A Novel of Suspense Featuring Mary Russell and Sherlock Holmes. Because for that first half there was no suspense and almost nothing of Sherlock Holmes.
It did redeem itself for me in the second half, but this certainly wouldn't be where I'd pick up the series, and if this is where you did, and you didn't care for it, I'd try again--the first in the series, <i>The Beekeeper's Apprentice</i> is one of the best--but so are several of the other books. I'm not the only one to be disappointed in <i>The Pirate King</i>--this has the lowest rating of any book in the series on Goodreads, averaging 3.34 stars while most installments are over four. I think what I find a weakness in the series comes ironically from a source of its strength. The books are varies in tone, theme, settings--even narrative devices. And as a friend pointed out, the light-hearted nature of the book does make a welcome change of pace after the grimness of the last two books. But even though humor is a welcome element in the books, the humor here was either too broad for my tastes, or just not something King's forte.
That said, I did give it three stars because ultimately I enjoyed it, and am glad I finished it. There's only one more book in the series now for me to read, and I'm going to feel a pang when I finish it and have to wait for King to publish the next one.