"What was the purpose of the thread-disc behind the first eye?"

There's a sense of alertness/interest from Cold River, although she doesn't say anything directly.

"Ah! That was the part I'm proudest of, I couldn't have held the rest together without it," the Assistant enthuses. "It's a spiral weave. It holds the structure of the magic in place and binds it together to form a foundation for the eyes, and then through the eyes for the rest of the mask. It's very tricky to get it just right! That kind of internal support structure is less necessary for my standard arrangements, but when I'm going out on a limb like this I really have to work to make the magic stable and functional. It's part of why I like working in spirit so much more than other materials—a proper spiral weave can be incredibly difficult to achieve in metal, because it's so hard to give it a sufficiently even twist, and for wood you have to approach things from an entirely different angle, by selecting your blocks of wood and carving the mask components at just the right places to fit with the grain so you can lay the magic inside it..."

Their voice is beginning to get fainter, and the misty clearing itself seems to be gradually fading from view. Baruti might not have much more than a few minutes left here, if that.

"I think I could probably cheat at that with my magic--would you like me to share the sense-impression of my magic, that's all it takes to get started on it in my world, although I should also warn you about the side effects--"

"Oh! Yes, that sounds very interesting! Please do tell me all about your magic! Although perhaps very quickly—sorry again about that, I always forget that finishing the mask means I won't have all the time in the world anymore—"

He doesn't bother with the standard telepathy form, instead simply commanding the spirit's mind to contain the sensation for magic-using. 

"Doing magic hurts, and there are three kinds, each with their own side-effect. Sympathy involves persuading the world and makes one more agreeable, Effort involves pushing on the world and makes one more stubborn, and Conquest involves commanding the world and makes one more imperious and less inclined to hear the word no. All these effects can be meliorated through meditation and self-examination and practice in behaving contrary to the direction the magic wants to push you," he says in a rush. 

"That's so interesting!" the Assistant says delightedly. "Thank you very much! I'll be sure to experiment as carefully as I can! Good luck!"

The voice gets fainter and fainter until it's barely audible; the clearing, similarly, fades away to both mundane and magical senses. Finally, Baruti is floating in a void with nothing but the intangible sense of Cold River coiled up in his soul to keep him company.

(It has been said that the transition back into the world may be rough,) she warns, and then reality crashes into them like a ton of bricks. He lands flat on his back on a muddy riverbank, with the wind knocked out of him and his vision sparkling; as it clears, he beholds for the first time the sight of a starry night sky through his mask's enhanced eyes.

The stars are astonishingly beautiful.

He stares up at them for all of three seconds, then pushes himself to his feet, sluicing the mud off his back with a small application of magic. 

(Well, that was interesting. What would you like to do next?)

(There are many possibilities,) she says. (In the most immediate term it would be prudent to secure food and shelter. Beyond that, what are your short- and long-term goals? Gossip among the spirits suggested that you wish to leave this world entirely, perhaps on a very short timeframe; is that true?)

He explains his situation with the other Great Mages and the reincarnations office. 

(Food and shelter my own innate magic can handle easily; what I want to do is extract as much low-hanging fruit in the form of maskmaking expertise you do not have from this world as possible before leaving.)

(Mask-makers are often secretive about their craft. With your mask and I to aid you, you would be very well-placed to pursue an apprenticeship, but I would not say that its fruit hung low. And there are dangers to roaming this world with a mask, which I think the Assistant forgets, having been in that place so long. I myself was killed by a hunter who devoured my mask's power. If what you seek is the most power at the least cost, it may be that the time to return to this—'office'—draws near already.)

(Very well, you would know better than I; I accept your judgment. I assume you will want input in where we go next. I shall have to ask him which routes will allow you to make choices as well as I.)

(An agreeable plan. I am interested to see how your magic works to move between worlds.)

(Watch carefully, then.)

And then he commands himself back in the reincarnation office. 

It's the same office that he left, with the same unseen presence behind the desk. With his new senses, he can see everything more clearly, but mostly what he sees is the same thing he already knew: the office and the desk and the papers are all manifestations of a single entity, woven from the same thread, unified by a single soul, and the cabinet is filled with countless more souls in some kind of stasis.

Mere moments after he arrives, the unseen voice says, "Ah! Welcome back! And," flip rustle ruffle swish, "welcome to you as well, miss!" The bureaucrat's eye appears between the stacks again and blinks at them in what seems to be a friendly fashion. "Shall I run the same search from last time, or have your parameters changed?"

"If there are paths that would allow her to make choices as well as I, I would prefer to be directed to those, where possible."

"Hmm. Do you mean paths that will offer additional sets of options given two choosers, or paths that will require consensus from both of you to proceed, or something else entirely?"

"I mean paths that will count her as a chooser and not just an--accessory to me." 

"I'm not sure that's a criterion I can sort on without understanding your practical purpose in wanting it. The two of you are in a situation where both are associated with a single physical form which only one of you can control. Very few paths are formulated with that kind of scenario in mind; I can't think of any offhand, though it's possible some would turn up if I searched the right parameters. Regardless of which path you take, you will retain the ability to confer with your partner and take her preferences into account. Some paths will have an administering entity, who may or may not be able to perceive the presence of a second soul, and may or may not regard the second soul as a separate chooser, and will react to their perceptions according to their nature. Some paths will have no administering entity, and their reaction to your situation will depend on their specific interface."

(What do you think?) he asks Cold River. 

(I, too, wonder about your practical purpose.)

(Very well.) "The same parameters as last time, please."

Mild amusement from Cold River.

Shuffle riffle swish raffle thump. The stack has arrived.

"Largely the same results, I see, though I can refresh you on them if you like... hmm, this one's new, but it's stamped Still In Testing, shall I take a closer look?"

"There can be no harm in looking." Pause. "I assume."

"Pathways that are harmful to consider have very clear warning labels!" the entity says cheerfully. "Here we are. The Tree of Fate. Part of a cluster with the Fay Path from last time, it seems. Medium-high power level, no known risks... but of course there's always some uncertainty with the untested paths. You'd likely be among the first choosers ever to try it."