No. I have no extensive experience with the Fae. But I can get my men to follow me anywhere.
(( Jacques is the one with a magical focus in crows, yes? Oh, this is going to be interesting. Excellent choice, there. ))
"Great, I'm excited, let's do this!" And before anyone else can offer assistance or objection, he waves for Jacques to follow him, and he departs from the hastily convened council meeting. Before he left, and in any ensuing discussion he indicates the reason he called for the meeting was due to the implied threat of having an additional Quaesitorial investigation ongoing, besides the one Tranquillina is currently dealing with.
Once he and Jacques are out of the chambers, "I don't want to take a lot of men, but you probably could use a translator, there's that fellow who showed up a couple of years ago, he speaks Slavic, judging by his accent. Miro-something I think he calls himself. I'd get him to go and act as your translator. Given that the covenant of Marchera Aqua appears to be under some sort of siege, I'd say a good fighting group, with one or two shield grogs for each of us. I'll pay for getting us as close to Marchera Aqua via portals, but we will have a fair walk. I'm currently fixing an Arcane Connection to Saraid, or whomever sent the letter. I'm going to attempt to communicate with her before we depart, after I've fixed the connection. So about a week or so."
[hr][/hr]
Once the connection has been fixed, he's going to fetch a magus of Mons Electi who is available (anyone can jump in) in addition to Jacques, and begin attempting to communicate with Saraid...
He will first Open the Intangible Tunnel with a total roll of 42. Total penetration is 22+ (1+4) * Penetration (3+1)=42
He easily maintains concentration for casting a Maintain the Demanding Spell and doesn't botch it.
He then casts a spontaneous version of The Ear for Distant Voices, but at touch range, which would be a 5th level spell his InIm CS in the aura is (17+6+2+5), and so he can do it without exerting fatigue or rolling; He also Maintains it with a MtDS: no botch on concentration or MtDS
He then casts a spontaneous version of Phantasm of the Talking Head but with a Sun duration through the Tunnel; CrIm CS is 28 vs a spell level of 15; He doesn't botch. So he will try it again and is successful.
Assuming all has gone well, he'll begin speaking to Saraid (if he couldn't hear anything with his Ear for Distant voices, he would have stopped, and let the tunnel close when the MtDS for it ended.
"Good afternoon Saraid. I was warmed to receive your letter. I wanted to let you know that it was well received, and I will endeavor to help my good friends of Marchera Aqua. Oh, and depending upon how long our conversation lasts, you'll need to pause while I cast some spells to maintain our connection. I've assembled a team to come help, and we'll depart in the morning." He pauses, "But the purpose of this exercise was primarily to ascertain whether your situation was continuing to deteriorate, and what additional resources I could bring to bear to assist you." Of course, it also delivers the message that Marcus has an AC and can penetrate her resistance, if this all works. 
Edit: Also at Weary fatigue level, -1 for all subsequent actions, but that shouldn't be an issue. Botching might be an issue, though.
2nd edit: it would be completely cool and fine with me if the Sun Duration Phantasm of the Talking head continued to talk as Marcus does for the rest of the day, so that whatever he says is relayed to Saraid. In fact, Marcus is kind of hoping that's the case, because once the Hermetic Phone call drops, he's going to tell anyone else some interesting facts about Marchera Aqua... 
((the focus is actually on the Corvidaefamily which includes Bluejays, magpies, Crows and Ravens. All accounted to be the smartest of birds. He just has a special thing with Crows due to his power to summon them and his familiar.))
First of all, that's technically scrying on a Magus. I don't know if Marcus would care, but thought I'd point it out. 
Secondly... as the Ear for Distant Voices takes effect, you start hearing things from the other end. First of all, there is Saraid's voice, in fairly decent Slavic.
"... and board, plus two Novgorod grivnas per man for each year of service. You can't ask for a fairer price than that."
There's a lot of noise in the background, the hum of many interlaced conversations.
Does Marcus continue with his Phantasm of the Talking Head plan?
In for a penny...
Marcus doesn't care. He can extricate himself from Mons Electi easily enough, that he's not too concerned about an investigation. If Saraid wants to push for the scrying after Marcus helps her, well, I'm sure he'll uncover something that could be used for blackmail purposes, namely the molesting of the faeries that precipitated this whole episode.
Okay. In lieu of common sense, please give me an Int+Magic Theory roll.
Nah, that's sufficient.
The fact that your spells penetrated with such relative ease suggest that either Machaera Aqua's Aegis is down or Saraid is not within the protection of the Aegis. Combine that with what you overheard, and it's quite possible that Saraid is -- at this moment -- outside the covenant, and in a public place. It's very out of character for her, granted, but from what she's told you about her situation, it's possible that she simply has no one else to send.
Given that, an illusionary head popping out of thin air and blabbering in an unknown tongue may have... undesirable side effects.
((Oh, I get that message as a player. But Marcus is here to help, as Saraid requested (oh so politely). Now, you're right. It wouldn't do to speak in a tongue not everyone can understand, so he'd speak in Slavic.))
Edit: Just realized. Marcus is like Draal, right now. Appearing at an inopportune moment. Saraid is the kind word, and Marcus is the 2 x 4.
[color=blue]"Well," Fiona (who is in her Petite Masquerade form) says, [color=blue]"that was quick and abrupt. Two of my least favorite attributes in a man." She has a playful, yet slightly nervous smile.
[color=blue]"I'm not sure just when he's leaving, but – just out of curiosity – who else is planning on going with him?"
((I will make up about 5 more grogs this weekend to take.))
Jacques left with Marcus so you can assume he is going.
((Thus the "else" in her question.))