We know there is chance of Murphy coming back,
But whether she actually will or not, I don't know.
I predicted on the forums, years ago, back when JB was still insisting that he had no plans to either write Murphy out, kill her off, or power her up, that he would at some point in the not too distant future be forced to write Murphy out, kill her off, or power her up.
That was no particular prescience on my part, just a recognition that as the story advanced and changed and the stakes kept rising, Karrin wasn't keeping up. Back in the early books, when Harry was basically a small-time Chanderlesque PI who happened to possess magic, she fit in perfectly. In those stories all the usual character roles of a Chandler-style PI story were present.
Harry the hard-boiled PI (though he wasn't hard-boiled yet back then, one interesting thing about the Dresden Files is that we're getting to see the hard boiling process play out, rather than meet the protagonist after he's already case hardened). He had the usual money problems, bad luck with relationships, etc.
Marcone was the local mob boss. Karrin was the cop he interacted with most often, usually as an ally but sometimes as an opponent. The 'scope' of the stories was mostly Chicago, local. It was a variation on the classic Chandler formula.
But as time passed, Harry grew into a global level major player, with major influence. The scope of the story reached world-wide levels many books ago. The players now are national governments, militaries, ancient conspiracies, archangels and gods.
Marcone grew with the story, becoming a freeholding lord, a Denarian, etc. Karrin just didn't. By the time of
Skin Game, when Harry recruits her as his gun moll for the upcoming operation, the problem had become acute. Harry simply needed higher power help than Karrin could provide, I suspect that's part of the meta reason why JB brought Michael back temporarily.
So I wasn't a bit surprised by her death. I knew a long time ago that JB was going to have to change his plans, he either had to sideline Karrin, power her up, or kill her off. He might have done both the latter in one stroke, but I knew he wasn't going to be able to keep her as was, because the DF is no longer a Chandler-esque PI story.
What I'm getting at with all this is that while I can certainly imagine ways to bring Karrin back into the story, ways that could fit with the setting...I'm not 100% sure JB is going to do it. If she comes back as a Valkyrie, she's not really quite Harry's Karrin anymore. If she comes back as human Karrin, it's both another 'death is cheap' moment (and too much of that wrecks any story) and recreates the previous problems.
but I was thinking. What if Jim finds a way to have Susan's back instead? Of course, the obvious way would be to bring Mirror Susan to Harry's prime universe, but I was thinking it would be better to find a way to resurrect the woman who gave her life for her child (and Harry). Of course, resurrection would normally be a no-no, but with so many supernatural entities around, who can say it is impossible?
Let me be clear, I am not such a fan of Susan, but it would be so good for Maggie Jr. and Harry to have her back. And the dynamics would be very interesting.
But I so hope not.
I think I said once before that when I heard that there was going to be a 'parallel time' story, when I heard Bob tell Harry that Spiderman is real somewhere, I actually physically winced. I've seen parallel time stories go sour so many times, and they create so many continuity and 'stakes' headaches, that I literally dread them.
I have seen good ones, but they're very much the exception. The old original Star Trek episode
Mirror Mirror, was a good one. The Trek novel
Dark Mirror, written by Diane Duane, was done as a nextgen sequel to that episode, and it was good, too. But the stuff the actual DS9 and other Trek shows did with the mirror universe was ghastly.
The trouble with parallel time is that it removes stakes. That is, if Character A dies, well...so what? If you have the necessary magic/tech to reach parallel time lines, and there are an infinite number of such, then somewhere Character A2, A3, A4, etc. are still alive. Your wife/husband died? Well, somewhere Out There in alternity, he/she is still alive, single, and waiting for you. Don't like how the last election turned out? Don't like how the last war turned out? If you can access alternity, somewhere there's a world that's
exactly what you wish for.
Sweating over a hard decision? Well, just think, you're going to choose every option, on some time line. Get married/stay single? You're gonna do both. Quit your boring job and take a risk on your dream career, or play it safe? You're gonna do both. And so on.
The multiverse is already messing up the Marvel movies, in a big way.
I've learned to have a lot of faith in JB from experience. Several times he's made writing choices that worried me, and turned out to be good. So I'm not panicked...but the alternate-reality story is the one I'm looking forward to least, the one part of me still sort of dreads.