The e-ARC of Eye of the Storm, John Ringo's latest addition to his Legacy of the Aldenata series. From some of the things the Barflies have been saying on Baen's Bar, it looks like he's taking the series in a completely unexpected direction.
The original books all focused on the war against the Posleen, a race of ravenous centaroids who stripped whole planets the way locusts do a field. The side trilogy he wrote with Julie Cochrane dealt with the covert war against the sinister manipulations of the Darhel, a race of thwarted warriors who instead focused their aggression into legal shenanigans, with the intent of enslaving every other race in the galaxy. The novel The Hero, which he wrote with Michael Z. Williamson and was set about a thousand years after the Posleen attack on Earth, implied that the intervening years were filled with battles against old-style Posleen, along with a new race known as the Tselk who might or might not be allies of the Posleen.
But from what I'm hearing on Baen's Bar, it looks like Ringo's tossed out the continuity he's created in The Hero and gone in a completely unexpected direction to introduce a completely new enemy from another dimension. We'd gotten one surprise at the end of Honor of the Clan
when the Himmit rescuers of the O'Neal Bane Sidhe referred to their rescue craft as being a battleship of the Himmit Empire. Of course the Himmit were always mysterious, right from the very first book when we were told that they were not among the original races of the Galactic Federation, but had come later, after the Aldenata had vanished. There had been some speculation when Honor of the Clan came out about the nature of the Himmit Empire -- whether it was hidden beyond the boundaries of the Galactic Federation, or somehow within it. But now I'm wondering if the Himmit are from this other universe from which the new, bigger, badder, Bad Guys are coming from.
I'm going to be very interested in seeing exactly how Ringo's handling this. I've seen far too many authors of long-running series getting into the trap of feeling they have to top themselves with bigger new ideas in every successive novel, until it feels like they're just dialing the volume up louder and louder. Other times an author's efforts to add new things into an established series instead end up losing track of the elements that brought readers to it in the first place.