Falko (who was there last time) has Latin 3, so he's probably good enough to describe it. If I remember correctly:
"The approach, it is long, but there's cover of forest - most of the way, but then close to the end - palisades rise, and some sentries keep watch - and trust me, those giants don't label us 'friend'."
Falko is rather proud of keeping the whole description in dactylic metre; others might swear there started to be a hint of a melody by the end.
((Fiona turned and went back inside with the Blacksmith when the group started to leave...and she probably hasn't noticed that they never made it out of the garden. Soo....she's not there 
))))
Thank you for your help.
Thinking out loud
Approaching under the forest cover is good. It leaves us at least the element of surprise. Now, there are 2 options. Stage a diversion so as to easily enter the camp, or use yet more stealth. I would favor the second option, of course. This should be possible, using a combination of Imaginem Magics and mundane stealth. We can maybe even allow to pierce the palissade at a chosen point, which should ease things even more.
To tranquillina
What do you think of it? have you some spells suitable for this? I'm thinking that we could take some prop, and use Creo Imaginem magics to give it the look and feel of that medaillon once we find it. That way, we won't alter the giants, nor will we have them coming after us for it. That is, of course, assuming we manage to steal it without being detected.
Now, fiona, where is that girl? We go of on a rescue mission, and first thing she does is dissapear on us?
He was so focused on the search for informations that he didn't even notice fiona wandering of 
Happy that this dangerous mage is not only on her side but asking her to weigh in on potential plans, Tranquillina ponders her capabilities. "Being this size negates many of my spells ... but I believe I could still render myself invisible, for example. And yes, I could create an illusion of the silver chain to leave in place of the real thing, if it came to that - I am sure you could as well."
She thinks a little bit more. "If we did want to incorporate stealth all the way through the plan - perhaps in concert with a diversion, as you say - it might be better if I returned myself to normal size. That way I could use my spells of instant transportation, for example. Of course, it would greatly increase my danger, were a giant to actually assail me."
((If I didn't write this before, Tranquillina definitely picks up an Arcane connection to outside the Blacksmith's house - a Magic rock or some such.))
I don't know.
I'm quite tempted to be stealthy all the way. Yet, this might be difficult to do. I don't know the place. If it ain't possible, it might be better for us to look at giants, but with different appearances.
For exemple, if I cast on myself the illusion of an old giantess, they might search me if I am spotted, but not her.
So we could, for exemple, do most of the travel as giantess, come back to our normal size near the camp, which will make us harder to spot, infiltrate it under the cover of the night and invisibility, steal the chain, and replace it by an illusion. Using translocation to enter and escape the camp being, as you notice, a good idea.
(Isen will do the same, although he sure hopes he won't have to abandon the grogs)
"Is the installation we seek to infiltrate a simple residence, or a war camp?" Tranquillina poses. "If the latter, the giants would probably search anyone, even a friendly-looking giantess."
[size=90]"In fact, if she were too friendly looking, they might search her all the more eagerly," Falko mutters to Jehanne, who laughs far more loudly than appropriate. Falko shrinks back under Tranquillina's glare, although Jehanne seems oblivious.[/size]
"I wish I could transport the entire group at once," the maga laments; "then we could sneak one person in for an Arcane Connection, and return suddenly in force. But I fear I am not strong enough, even if we were all normal-sized."
((Looking at his character sheet, I think Isen could ceremonially spont a spell that teleported a normal-sized group 50 paces to an Arcane Connection location. But without the ceremony, it would be a long shot - so how would we get out?))
"Perhaps we need to make the main choice: stealth, or force, to get to the chain we need? If by force, then the forest itself will probably provide enough cover on the way." Tranquillina knows which option she is more suited for ... but having several enlarged soldiers around puts the other option within the realm of possibility, at least.
Oh, I didn't intend us to enter the camp openly. More sneakily, under the cover of night and magic. The Giant look is for travel.
Have no regrets. When infiltrating the camp, the less we are, the better, if we are to be sneaky.
In fact... I think sending a grog in might do the trick. With any luck, we can bind his image and voice to an item we'll keep, thus allowing us to see and hear him while he'll be invisible and inaudible to the giants. And if we take an AC to him, we can come to his rescue if need be.
I'm in the mind that open, direct confrontation should be avoided if possible, unless you is sure to win. And even then. All kind of things can happen in a battle, and you can never be sure to get out of it alive, or that your ennemy doesn't have some hidden trick. My master... He's more the backstabbing kind, yet I can't fault his effectiveness.
We don't know how many giants there are at this camp, nor their strenghts, nor if they can muster reinforcments or alert people we would not want knowing we're here. So I say we try stealth, and resort on force if it fails.
Tranquillina is relieved that she will not be part of a frontal assault on a fortified position guarded by denizens of the Magic Realm ... although a small part of her is, to be honest, a little disappointed. Still, she knows how frail the body can be, and doesn't want to imagine what a solid blow from a giant would do to her.
((OOC is easier here: she likes the [strike]redshirt[/strike] grog idea, although she points out he would be limited in his actions - he could steal an item, but not render it invisible or leave a replacement. We could indeed keep ACs to him for our own transport back and forth, although it would take a sponted spell to spirit him out magically. We could possibly send Ignitio instead of a grog?))
((In terms of spells, she discusses with Isen a version of The Captive Voice, but Touch instead of Voice and Diameter instead of Sun, for a level 15 spell - should be quite spontable here, and time to rest afterwards. Instead of putting the grog's voice in a bag, attach it to a tree stump somewhere we can stay safely. And a second, similar sponted spell for his image in addition to his voice. He'll still cast a shadow, so he'd have to be careful. Also, we'd be able to see and hear him, but not what he's seeing and hearing (although Tranquillina can use her eavesdropping spell, if she can keep concentration on it). Tranquillina also mentions offhandedly that she is able to dismiss Imaginem spells with ease, when it becomes necessary.))
((So who's doing what?))
Sorry, falling behind.
We'll travel as giants towards the camp.
Once near it, the goal is to use the forest cover to come near it, and send an (essentially) invisible grog in it.
Yes, this is what I thought (I guess, since I don't remember what that spell does, but judging by your descrption, this is it)
I figured that we could have an AC to the grog, jump in when he's found it, cast the needed spells, and jump out, while he'd make his exit on his own, just liek the entrance.
I'd be against using Ignitio, due to his MR, unless you've got an idea?
Okay, so just to confirm: we all stay giant and sneak through the forest until we're as close to the giant fort as we can sneakily get.
Then: we kill the illusion on Isen, and we MuCo both Tranquillina and the Chosen Grog down to a manageable size (easier to cast spells on).
Then: we spont image-stealing and voice-stealing spells on the CG. Each mage takes an Arcane Connection to him. He sneaks around until he finds where the chain is.
Then: the mages come, invisible and all sneaky like, and get the chain/leave an illusion in its place, and use ACs to teleport out again. CG sneaks his way out.
I see many things that could go wrong. Let's do it anyway 8)
If you agree, charge ahead!
So, who's playing the grog, and which grog is he, and does he have any stealth to speak of? 
JL: Sorry, no idea. I don't even remember what grogs are with us 
Not-so Quick search :
Isen: Bernard, Brionne.
Tranquillina: Jehanne, Falko
Fiona: ???
Jacques: Orrand
Orrand isn't very stated, so it must be one of the other 4.
Yes, save that, unless the grog is discovered (in which case we need to use force, there's no need for all the magi to teleport inside the camp. One is enough.
And of course several things will go wrong 
No plan survives the first contact with the ennemy.
I can't find stats for Brionne. Of the others, Falko handily has the best Stealth. He's also got great Quickness which could be useful. Plus he'll be more fun to listen to
Casting time for Tranquillina (we can rest two minutes between each spell).
- Spell to shrink Falko: As Preternatural Growth and Shrinking, but -1 magnitude for Diameter instead of Sun, +2 to affect a Size +5 target, for at least level 20; rolling up to reduce his size as far as possible, but not below 0. Casting Total: Sta -3 + Mu 9 + Co 27 + Talisman attunement (Corpus) 3 + aura 12 + stress die 4 = 52, halved is 26. Level 20 would shrink by -2, so level 25 would shrink by -4? That makes Falko size +1, which is small enough to cast normal Corpus spells on - probably good enough.
- Spell to shrink herself: As above, but an additional -1 magnitude for Personal instead of Touch, for at least level 15; rolling up to reduce her size as far as possible, but not below 0. Casting Total: Sta -3 + Mu 9 + Co 27 + Talisman attunement (transform self) 4 + aura 12 + stress die 6 = 55, halved is 28. Level 15 would shrink by -2, so level 25 should shrink her all the way to Size 0.
- Isen, you do want the illusion on you destroyed, yes? Assuming so, Tranquillina has Unraveling the Form of Imaginem as a formulaic, at level 10: Sta -3 + Pe 14 + Vi 5 + Mastery 1 + aura 12 + stress die 8 = 37. Cancels an Imaginem spell of level 10 + Unraveling 3x(Mastery 1) + 10 + stress die 4 = 27, easily beating the illusion's spell level of 5 (hmm, maybe Isen could have cancelled this himself).
- Tranquillina also has Veil of Invisibility: Sta -3 + Pe 14 + Im 10 + Mastery 3 + Talisman attunement (suppress image) 5 + aura 12 + stress die 3 = 44, good enough.
- And when it comes time, she'll cast The Ear for Distant Voices to eavesdrop on Falko's surroundings: Sta -3 + In 6 + Im 10 + Mastery 1 + aura 12 + stress die 9 = 35, good enough.
(Edited to add: eep, all of those rolls should have included a -1 penalty for her Vis Allergy. Nothing was on the edge though.)
Isen and Tranquillina will both take a hair from Falko (or something else easier to keep track of?), and a stone from the ground at their setup point in the forest near the giants' fort.
I assume Isen will spont the spells that capture Falko's image and voice. Then we should let Falko practice for a few minutes and make sure everybody gets used to what's happening. We should warn Falko in particular that he'll still cast a shadow.
Isen, will you make yourself invisible, or do you want Tranquillina to do that?
Also, since invisible people with shadows will prefer darkness, Tranquillina will cast Eyes of the Cat on herself and Falko. Even without duration reduced to Diameter it's only a level 5 spell, which she can cast with non-fatiguing sponts: Sta -3 + Mu 9 + An requisite 8 + Talisman attunement (eyes) 6 + aura 12 = 32, fifthed is 6.
Alright travel to the [strike]Steading of the Hill Giant Chief[/strike] giant chief's hall is without difficulty. There are a few farmers that they spy, but they keep to themselves, and no apparent patrols on the road.
The charred remains of the palisade is there and no work appears to be going on to repair it.
Falko is invisibled and then...
Fiona's sitting this thread out (well, actually, the player is, but still), except for enjoying her time with the Blacksmith, but her new shield grog Jehanne is with the group.
Brionne's stats are here, but I don't know if he's been advanced since 1220. He's not on the Wiki yet, though.
Yes, he will.
Perdo 6 + Vi 4 + Sta 2 + Aura 12 + Talisman 3 = 27 / 5 = lvl 05 without fatigue.
Using the general guideline to "cancel effects of a speficif type with level less than (level + 4 mag + a stress die) means that, even if going for touch range, he can cancel Imaginem spells of lvl (5 + 3 mag + stress = 20 + stress), which is enough.
Yes, he will.
Isen ReIm is 26 + 2 + Sta 2 + Aura 12 = 42.
Using ReIm base 4 (make an object appear, to one sense, as it it's attached to an object defined at the time of casting), +1 touch, +diam, + 1 to affect a changing image, +1 to have it change along the object, = lvl 20.
He's gonna use the same one with sound, only with duration Concentration, so that he may drop it if needed.
WTF??? Invisible castle is no longer registered domain??? And I haven't found a diceroller that allow me to link results
It should be ok, but there's always a slight botch chance.
He'll hesitate a little. He doesn't like to lower his parma like this, but he sucks so much at PeVi, he's not sure he can do it. He won't say this to tranquillina, of course.
Just do it. I prefer to avoid spontaneous magic, given the chance. Thanks.
((Hey, cool, it's already a Touch range spell!))
"I understand your caution with spontaneous magic; but I know this effect well," Tranquillina reassures Isen, placing her hand upon his shoulder. She then casts Veil of Invisibility upon him, without words or gestures just to show off. 8) ((Sta -3 + Pe 14 + Im 10 + Mastery 3 (no words/gestures penalty) + aura 12 = 36 even without the die, and there shouldn't be a botch chance.))
Of course, he'll say nothing.
But in his foremind? Luckily, he can ascertain at once that he's invisible, and thus that she has cast the right spell, because, otherwise, there would have been no way for him to know what she's done, which would have made him very uncomfortable
So, I guess we are set, then.
Oh, invisible castle seems to work again 
So, roll for the 2 Rego Imaginem spells: