Following up on this from before...
Also, there are some word usages that sound to me like the ghostwriter is British, like "lav" for bathroom, "liner" for garbage bag, etc. Castle wouldn't use those.
Actually, having just finished Heat Rising
, I'm now certain the actual writers are series creator/showrunner Andrew W. Marlowe and Tom Straw, a mystery writer who was mentioned on the cover of the first book and has often been suspected of being the writer. In the acknowledgments (which are supposedly written by Castle but are an opportunity for the real writers to express their thanks), there's a paragraph thanking both Andrew W. Marlowe and "Tom," in such glowing terms that I think it must be the respective writers thanking each other. Also, there's a mention in the acknowledgments of Marlowe's wife (a fellow writer on the show) as someone who's "always beside me." Moreover, just from reading the book, I realized that the Jameson Rook character (the surrogate for Castle) talked exactly
like Castle, complete with an almost audible Nathan Fillion influence. It would be difficult for anyone other than the showrunner, the person who does the final polish on all the scripts and shapes the characters' voices (and works routinely with the actors), to capture that voice so exactly. So I was convinced it was Marlowe even before I read the acknowledgments.
But since Marlowe and Straw are both Americans, I can't explain the British word choices. It's odd.
Anyway, in light of what I was saying before about feeling that the show is becoming too broad and fanciful, I find it ironic and a bit incongruous that the Nikki Heat books, which are supposed to be works of potboiler fiction written by Castle, have more verisimilitude and naturalism to them than the show that's supposed to be Castle's real life (in terms of things like police procedure/organization, the portrayal of New York City, and the like). You'd think it'd be the other way around.