This trilogy---Changelings, Maelstrom, & Deluge---picks up the story begun in Powers That Be and its two sequels. Unfortunately, the writing isn't nearly as good. I found these novels hard to put down, but thoroughly disappointing in the end. The characters don't develop, and the situations of danger they find themselves in are all melodrama.(view spoiler)[ That is, everyone is continually in danger, with barely a moment to catch their breaths before they're off to another exciting event. However, everyone escapes by a hair's breadth at the last possible second, essentially uninjured, and without any change in their character or outlook. Villains are eventually conquered, but not until the last few chapters, when suddenly everything comes right in a whirlwind set of hearings in which all our heroes are miraculously believed without argument, even when their testimony is clearly implausible. How convenient.

Between geological disasters, human plots, world-hopping, and exciting alien encounters, there's not a moment to stop and say, hey, wait a minute, how come no one changes (except to get older)? The most interesting character development occurs in Sky the Otter, as his world view is considerably widened by his various experiences with the twins. The twins themselves begin as precocious children who take stupid risks and end as precocious pre-teens who ... take stupid risks. The other characters are merely cardboard. For example, the alien "deep sea otter" people could have been an interesting addition, but because there are no point-of-view characters among them, they disappear for large chunks of the books, only to appear as a deus ex machina just before the wrap-up. After half-drowning some and rescuing others, they disappear again.

Sadly, Yanaba and Sean, who carried the first series really well, are just as cardboard as the rest of the characters. They go through this second trilogy without ever really getting a handle on either their own reactions to being a species-blended family or the planetary society they're supposedly in charge of. Their marriage and family could be so interesting if the authors had actually gone there. Yanaba continually grieves over being "left out" of the twins' & Sean's selkie adventures, but the emotional fallout of this division is never resolved. It's just there to harrow us up for a few pages before the authors move on to the next adventure. (hide spoiler)]

I wish McCaffrey and Scarborough had written a family drama about living on Petaybee, with occasional interference from galactic politics, instead of an adventure yarn about galactic politics, with occasional interference from family life. They've got such a interesting blend of a society here, with multiple sentient species in an interdependent society. These books could have been a much better tale.