Did anyone think of the Terminator movies when Esk mentions needing to save her son? Time travel. Mom protecting her son. Near unstoppable enemy that can take the form of other people. Fire.
It has been mentioned that Preston may be Esk's son, though I'm not sure. If Esk had mentioned that before the final encounter with the Cunning Man, then I could believe that she had to do something to keep him safe from him. But she says it after that, so it seems to be just an open plot thread, unless there is some timey whimey involved.
And Preston says this about his background:
My mother taught me to read and write, much against my dad's wishes, and since that meant I was no good for a proper job, I got packed off to be an apprentice priest in the Church of Om.
So for the theory that he's Esk's son to still work, Preston would need to have been given up and then adopted. It doesn't quite add up. But one thing is for sure, if Preston is Esk's son, we will hopefully have a future book about it and anything involving Preston would mean more Tiffany.
Regarding the plot with future Tif, I can't figure out any real point to it. Future Tif shadows Tif around but doesn't seem to have done anything other than to observe, save the mention of getting wind into the flames at the end, which seems contrived. It seems like Future Tif is just a plot device to reveal to the reader (and Tif) that she gets the fairy tail ending of being happy and in love. If that is the case, then Esk herself is only here to enable that plot device. I am happy to see Esk again since Equal Rites was my first Discworld book, but story wise she seemed tacked on.
I kept thinking that the witch shadowing Tif was the beautiful witch that died with the Cunning Man. Didn't Tif sometimes say things that seemed out of character during the book? For example:
* She says to Letitia 'Stupid woman. Stupid woman! Or silly woman, if you prefer."
* And then she suddenly says to Roland, "I will marry you."
* And where did "Leap knave. Jump, whore." come from? Maybe from Mrs Ogg...
I kept thinking that she was somehow being controlled or influenced and I naturally thought it would be the spirit of the beautiful witch, who is somehow hiding in Tif for some reason related to the Cunning Man.
It would be a time travel fan's delight if the beautiful witch turns out to be someone Tif knows, like Esk, who escapes the fire by time traveling. And her son's father is the Cunning Man. Yeah, loopsey doo. Speaking of time travel, I loved Thief of Time and would love a return to that plotline. I am curious if Lobsang and Susan got together. I hope these 'happy ending pairings' doesn't mean we that never hear from these characters again (margaret + verence, mort + ysabell, <gulp> tiffany + preston).
But oh I so enjoyed this book. Her hookup with Preston was not obvious at first and I rather liked how that relationship evolved. It would have been sad if Tiffany had followed Granny Weatherwax in having a loney life.