"So long as the influence of the Infernal does not rise above it."
Excellent points one and all. I have a thought. A little bit of recon to get a sense of the mystical layout of the land. Arachne, you have the most skill at both Intellego and Vim. You and I will take a carpet, fly around over the city invisibly. It is an effect of a magnitude to detect auras of different types and their power. We will check both sides of the wall, city and suburbs. Try to find spots were the dominion is weakest, but not infernal, and hopefully favorable to magic.
If it wasn't for the Dominion, Arachne could do this without Fatigue !
Base 1 to determine if a specific type of aura is present, base 2 to determine the power of a specific type of aura, +3 Sight, for level 4 to Detect and level 5 to Determine.
Time for a little mechanics, I'm afraid. I figure for Arachne to cover any reasonable part of Paris and its suburbs, we're talking at least 30 castings of each of the two spells. I'm less worried about the spell to detect the presence of a Dominion Aura, since Arachne can still manage that even non-fatiguing with a -9 from a Dominion Aura of 3. (I'm assuming that the penalty comes before dividing by 5 or by 2, not after; is that right?) There are certainly 4s and 5s in the city and environs, but the 5s can easily be avoided just by avoiding cathedrals and the like, and the 4s mostly so. But the spell to detect the strength of the Aura would be fatiguing for Auras of 3 or better. And there's no telling where Infernal Auras are, though you could guess. In the end, I'd say that she'd have to make 20 stress die rolls to check for a botch. That would give you a reasonable idea of general areas of Aura coverage, though it won't be by any means comprehensive. And you'd only be guessing for the higher Aura areas.
Also, to cover Paris and its suburbs, I'm guessing it would take at least 2-3 hours of effort. And during that time there's a chance (not a great one, but a chance) that Arachne would be seen by someone with Second Sight.
Given that, is it still a plan you want to go through with?
Technically infernal auras can be detected, as long as there isn't a demon involved in concealing them- so a 'natural' infernal aura around say a den of iniquity could still be detected.
[]It wouldn't be Arachne. It would be Roberto with help from Arachne. 
[]And it isn't a plan. Yet. It is roleplaying. Roberto thought of an idea and is passing it by others for input.
[]And not many people would, in real life, sit there and think of all the statistics and probabilities. Maybe C-3PO would, but not Han Solo.
Roberto is the Han Solo type 8)
Never tell me the odds!
Hey, this is the guy that goes into things figuring a 1% chance of success at a long shot is infinitely better than zero for trying nothing.
There is one time, in Novus Mane as pure PC, he made a ship fly knowing full well that he (I) would have to roll a 1 followed by a 9 to be able to succeed by spending all his Confidence
Reckless and Overconfident :mrgreen:
[]Yes, penalties and bonuses come before division. And I agree with Silveroak. It is not the Infernal that is undetectable. It is usually quite obvious, and practitioners are never able to hide it. Demons can hide it. Demons are special, for they are all unique Divine creations and were all once angels. That's my take on it. But in RAW, the neutral medium we agree on, it gives specifically demons the power to tell undetectable lies and hide things. Infernal Animals and Infernal Wizards cannot hide so well.
[]If you allow Ceremonial Casting and Words & Gestures, I count a total as high as 38. Minus 9 is 27, divided by 5 is 5.4
[]I just thought of a radically different idea, because I (the real me) am much smarter than Roberto.
InVi15 Detect (base 1, +2 Sun, +4 Vision)
InVi20 Measure (base 2, +2 Sun, +4 Vision)
But I am not sure Arachne can hit that, even with Fatigue. Still, I bet Roberto will wind up inventing one of these in a latter season. That's the way he works, learn what he needs after he needed it 
Let us scale back a little bit.
The situation is that the objective is located in disadvantageous territory. We are looking for a forward position, preferably with conditions less disadvantageous. A lower Dominion, a Lacunae, or a Magic or Faerie Aura. Detecting a low Dominion is easy. Detecting a lack of one could mean Infernal overlap.
So really, what we need is only two spells. One to measure the Dominion. That will be the hard one. The easy one will spot check blanks for the presence of the Infernal. If there is no Divine or Infernal, there is either a Lacuna/No Aura, or one that is Magic or Faerie. These conditions are all favorable
[]How much night time is left?
[]Mind you, this is all OOC brainstorming. Fixer has yet to weigh in with what Arachne thinks she can pull off and what would work best.
True, but people would get a general feeling that 'this isn't entirely safe' based on their understanding of how things work in general. (Think: "I've got a bad feeling about this.") That was my point in setting the numbers out. Roberto and Arachne would know instinctively that this isn't entirely safe from a Warping standpoint. Roberto (or Arachne) would be pushing their abilities and pressing their luck, and might suffer some Warping from the effort.
Frederika can find infernal auras pretty reliably - especially the nastier ones: they have a bad habit of making her feel very, very ill. Not that I think this has ever come up. But if you see her get dizzy, queasy, and begin to leave an area with due urgency, then you can bet something unpleasant is around!
Most people. But Roberto isn't like most people. :mrgreen:
Reckless and Overconfident. And full up on Self Confidence. It is up to someone else to think more cautiously 
And stand up to him and tell him he is being reckless...
... bye, have fun storming the city!
Vibria is Flambeau. This is Roberto's mission, and she is his soldier. Hers is not to make reply, hers not to reason why, hers but to do and die. Into the valley of Death will stride the Flambeau.
I'm assuming the following spontaneous spells:
Sense of Divine Power
InVi 2
R: Touch, D: Mom, T: Ind
This spell tells the caster whether he is currently in a divine aura. It does not give any further information.
(Base 1, +1 Touch)
Sense the Strength of Divine Power
InVi 3
R: Touch, D: Mom, T: Ind
This spell tells the caster the strength of the divine aura in which he is located.
(Base 2, +1 Touch)
Roberto has a basic +11 CT for InVi. If you put that in a Dominion Aura of 2, that's 11-6=5; divided by 2 is a total spontaneous casting total of 3, which is enough to detect the strength of the an Aura 2.
Even with exagerrated gestures and loud words, however, Roberto can only get up to a +13 CT for InVi. If you put that in a Dominion Aura of 3, that's 13-9=4; divided by 2 is a total spontaneous casting total of 2, which is not enough to detect the strength of an Aura of strenght 3+.
I see two options. First, Arachne does the casting. She has the numbers to support that. Second, Roberto does the casting, actually determines divine auras of 1 or 2, and simply assumes that where he failed was a divine aura of 3+. Not as accurate. And it doesn't account for infernal auras. But it might be good enough.
If Arachne is going to be doing any of the casting, I'd like Fixer's buy-in on the plan.
In fact, Arachné has Weak Spontaneous Magic, so she can't spend fatigue on this!
Due to Spell Foci, she could manage a fatigueless lvl 05 in a lvl 03 divine aura, so technically I guess she could do a lot of castings, but at the same time, that's also the best she can do.
Funnily, very much no, and a good yes.
Non-divine Sights would get a hefty -9, but Divine ones would get a +3 or more... And these are probably the ones we need to worry about the more.
People usually don't look up, even now when we have taller buildings. Still...
To Roberto:
I fear you may be somewhat overestimating my abilities, my dear. I am a spider, patiently weaving her spells, not a hawk rushing towards his prey. Mind you, I'm not keen about flying over a city housing one of the greatest cathedrals of france. All we need is some monk gifted with God's Sight looking up, or the wrong angel having a bad day, to have a bunch of men-at-arms on our hands. Now, if you give me some time to think, I may be able to fashion a little something that should allow Horus, which is, mind you, a little less obvious than a flying carpet, to perceive what we need. Or not, I'm not sure I can do it here. Dominion, dominion...
(In short, gotta go!!!)
The chance is remote. We're talking a multiple exploding stress die. Nothing that would even register with Roberto. But it is possible, which would register with Arachné.
Right now you are at an inn outside of the Dominion aura. This may be your last chance to cast spells without a penalty.
Sigh...
There is a possibility, but it will delay us. Don't count on me afterwards, I'll need my rest.
There's not much I can do under the might of the dominion, or deprived of my tools. But if I can leap back to Andorra, I can fashion a crude charm for Horus to wear. Nothing very durable, since my priority would be to weave the spell, but it should last long enough to do the trick. Of course, this would take me several hours, about 6 or 7, and thus pin us here in the meantime.
I'm not sure that'd be worth it anyway, since most casting we'd do would be outside our base of operations. It could also put Horus at risk
Teleport to andorra, use Craft Magic to weave a small hood for horus. Something that'd allow him to perceive Dominion aura of various strengths. So, basing it on "Sense the Strength of Divine Power", that'd be:
InVi 25
R: Touch, D: Sun, T: Vision
This spell allows its target to see auras of divine power as golden lights emanating from places, the more powerful the brighter.
(Base 2, +1 Touch, +2 Sun, +4 Vision)
She's got the InVi casting total for it. Afterwards, Horus could fly and do a sweep of the town.
She's obfuscating a little, of course. Old habits die hard. The dominion is crippling, but much less than her Weak Spontaneous Magic, so she's covering the one with the other (If people think she's susceptible to Divine Power, all the better!). She's also exaggerating her reliance on her workshop. And this could take her a lot less time if rushing things (she's also channeling Scotty here).
"The risk to Horus would be minimal," Lucas says. "He'd simply be just one more bird flying over Paris. The fact that he had a hood on would merely make him look like a hunting falcon. I doubt he'd draw much attention, if any. And I'm sure he'd be willing to do that service, right Horus."
"Indeed," the falcon replies. "I'd be happy to oblige."
"The real question," Lucas adds, "is whether we can wait six or seven hours for the hood to be fashioned. That's up to you, Roberto."
It will be at least that long until the gates open...
That's true. If Arachne works through the night, she'll be dog tired in the morning, but would have the hood.
Figure it's about 8 pm right now. Dawn is about 7ish. So you have about 11 hours before the gates open.
So it is Early March?
Early March would put it still in winter. I'm guessing late March, possibly early April.
Given that, I checked the Internet and sunrise in Paris is about 7:30, while sunset is about 8:20. So to be perfectly accurate, it's probably about 10:00 PM, and the gates to Paris probably open at about 7:30 AM.
No, no. That is a waste of too much time. Good think-tank action though. It is good to know that there is no Dominion right here in this place. At least not at night. We should perhaps set up a remote base here, set up a spell/crafting sanctuary. Arachne, if such a charm is feasible, craft one or two of them if you get the chance. There are easier recon methods. We should rest up. Tomorrow, two parties enter the city. One will set up a warehouse base, another will set up a safe house base. Fredrika will infiltrate the school. And one team will remain here to set up sanctuary base.