The symbology of pentacles or pentangles mean nothing in terms of how Demonreach is connected in time, they are just symbols like block printing. They are two dimensional.
Jim does callouts.
The law that forbids time travel says.
Thou Shalt Not Swim Against the Currents of Time
Out of nowhere in Dead Beat,
"It gets sort of Zen after a while," Butters said brightly. "Life is a journey. Time is a river. The door is a jar."
And finally in Changes just to be aggravating Jim tells you of a river that flows uphill.
I checked my mother’s memories and nodded as I reached the pitcher’s mound. “Okay, folks. First leg here. Should be a simple walk down a trail next to a river. Don’t get freaked when you notice the water is flowing uphill.” I stared at the air over the pitcher’s mound and began to draw in my will.
Now this appears to be a metaphor about the arrow of time.
Now remember how Ivy is spoken of in Small Favor.
“Drive one insane,” Luccio said. “Yes. And it generally does. There is a reason that the historical record for many soothsayers and oracles presents them as being madwomen. The Pythia, and many, many others, were simply the Archive, using her vast knowledge of the past to build models to predict the most probable future. She was a madwoman—but she was also the Archive.
Now in Turn Coat with Rashid,
Then he did something strange. He exhaled slowly, his living eye closing. The gleaming steel eye tracked back and forth, as if looking at something, though I could only tell it was moving because of the twitches of his other eyelid. A moment later, the Gatekeeper opened his eye and said, “The chances that you’ll survive it are minimal.”
And now the Mothers in Cold Days.
Calculation and thought flickered through those green eyes, faster than I could follow. "Ah, yes. I see," Mother Summer said. "So many new futures unwinding."
Both Rashid and the mother seem to be using calculations of the paths forward at specific events, Rashid looking at the possible outcomes in Turn Coat and the Mothers looking the possible futures after Harry learns one of the names of the Adversary. This is what I have so far about predicting the future in the DF and traveling in time.
