As I've been going through Castle for the 4th time, it struck me early on just how great the Kevin Ryan and Javier Esposito characters were. They were totally different from each other, but also perfectly complementary characters. And the actors who played them, Seamus Dever and Jon Huertas, were just phenomenal in the roles and they had unreal chemistry together.

There were a few episodes that focused on them, and those were some great episodes that didn't suffer from the reduced screen time for Castle and Beckett. They worked really well. Which got me thinking...

I really would have loved to see a Ryan/Esposito spinoff series after Castle left the air. Yeah, ratings on Castle had been down (mostly because half of the 8th season was kind of crap, and the other half was just pretty good, following a mediocre 7th season), but if the producers had been able to sell ABC on a Ryan/Espo show (with a scaled down budget since the Katic and Fillion's salaries would be gone) would you have been interested?

Obviously, since I started this thread, I would have totally been down for a Ryan/Espo show. My family all agree as well. The characters and the actors playing them were just so good, so much fun, that a series focused on them likely would have been wildly entertaining. They could have kept Lanie, too. Tamala Jones was great in that role as well, and had great chemistry with Huertas.

It's just a, "What If," kind of thing, I know, but I think ABC missed an opportunity to continue the Castle-verse with a great show. And Fillion & Katic could have guest starred every now and then, too.

Maybe I'm just crazy (maybe??), but I really think it would have been great.

I would have watched it; those two were a hoot.

To me, it doesn't feel like it's only been 3 years since Castle was cancelled. It feels more like 4 or 5 years to me for some reason.

It remains one of my favorite shows from the last 20+ years, though. Every time I go through the show I still love it. And one of the things I love about the show is the supporting cast (Montgomery, Lanie, Gates, Perlmutter - I love Perlmutter, and, especially Ryan and Esposito).

I am also going through the series again. I am about midway through season 5, which according to rumor was when the relationship between Fillion and Katic really started to implode. You can see a definite decrease in quality. A) there is a normal falling off after 5 seasons of most shows and B) I guess it got so bad they didn't even like to share screen time which is why they started separate storylines.

Getting back to the original question. Those two were fantastic supporting characters. I think Huertas more than Dever. Dever was OK, he was just a little more standard template fare for me than Huertas. For a great episode with them, watch the one where the rock star is murdered while they are being filmed for a documentary. Esposito suddenly hamming it up for the cameras was hilarious. Devers reactions to his hambone was great too.

Having just finished the 5th Season I think the overall quality was still there (if there was a drop, it was only slight), and the chemistry between Fillion and Katic was still good.

BUT seven episodes into the 6th Season you can see they've been given even more time apart. Each is on screen without the other in almost every episode. It makes logical sense within each story, but to see it in four or five of the first seven episodes is telling. A pattern emerges. The show is still good, but, yeah, in the 6th Season it isn't as good as it was two seasons earlier.

I actually like Dever more than Huertas, even though I really like both of them. Dever showed he could carry some serious drama with the episode where he goes undercover with the Irish Mob as Fenton O'Connell. He was fantastic in that episode.

But what makes each character work is how different they are from each other, but in completely complementary ways. It's like those two guys make up an inseparable team.

And that's part of the reason why I think a Ryan/Espo show would have been really good - and why I think a lot of Castle fans would have watched. I really think it would have worked.