Rodrigo shakes his head.
I disagree. This isn't an internal House matter. It is a business deal, between the Mercere and this covenant. If you keep acting humble and intimidated like that, they will rake you over the coals and you will wind up paying them to keep the bank hare and have access to their trade discounts. I know these people. They are my family too. And the sad truth is that they value money and power more than they value honor and family, or even pride. Having just about any member of another House present will give you the backbone you need. And a magus of Tremere, representing the influence and resources of his House, will be quite an asset to you.
It's like I said, they need you more than you need them. Mercere banking is set up like a pyramid. Harco sits at the top. The primary satellites are in Stonhenge, the Alps, Transylvania, and this one right here. This bank is the hub for the Summer three-tribunal area; Iberia, Provencal, and Normandy. What was known in ancient days as the Val-Negra tribunal.
They need a vault here or somewhere nearby. The two next best choices are Doisettep or Bellaquin. Doisettep offers security, but whould charge much higher rents and would inhibit traffic. Bellaquin offers higher traffic and many temporal connections, but many view it as unstable and on the verge of disaster.
Another reason why I think it is a good idea to get a Tremere involved is because the Tremere are the largest client and largest competitor of the Mercere banking system. A fifth of the vis in that vault is theirs. The Traslyvania hub is actually owned by the Tremere, they just pay the Mercere to operate it. I don't know what rank this guy is ([size=50]what was your name again?[/size]), but if he has the ear of the local Exarch, he brings powerful leverage to the table.
(snipped from earlier)
Carmen looks puzzled. How so? Which one is safe? To believe the legend or not to? Which is the safe interpretation? And do you think we should agree to the Locus transfer or not?
My name is Vocis. My 'rank' within my House may not mean much to you. Suffice to say that my sigil was earned as much by service to my House and the Order as by certamen. I do have the ear of my Exarch.
EDIT: corrected my mistake about how Vocis gained his sigil
(just to be clear: There was a Certamen involved, but it was ceremonial in nature. Which is not to say that the contest was thrown or anything. It was expected for you to win.
Ah. One of the books that I have that I've only glanced at or looked for info when I had to. I didn't realize that it had the distinctly non-European Jinn in there, after a fashion. (Or is that the Mythic European interpretation of what a jinn is? Hmmm....)
Anyhoo. Int 1 + ummm...wait. Never mind. Fédora doesn't have Magic Lore. Yet. Maybe someone can teach her someday.
Boy, this reaches deeeeep into the WABAC Machine. They're from the 2nd edition Covenants book, it seems, and a cursory Google search shows very little, if any information about them (and nothing on our Wiki). So. What does Fédora know about them? ((Int 1 + Order of Hermes Lore 4 + (die roll of 1, followed by a die roll of 10) dice total of 20 = 25. Or 26 if she gets to include her Specialization of House Mercere.))
As a total aside, it does make it easier for me to follow if there's something showing which character is verbing, rather than going back to the character creation threads to see which character whoever was posting about.
Oh, wow. Um...
Whatever you read in ArM2 Covenants mostly still applies, viewed from a 5th edition lens and considering that a generation has passed. Doisettep is a center for the traditional Cult of Mercery, and is a rival of Castra Solar for regional dominance of House Flambeau. Bellaquin is full of Jerbiton artists and prominent mundane associates. And Cathar refugees.
I've never read anything from 2nd edition. I just googled "Doissetep covenant ars magica" and "Bellaquin covenant Ars magica" and all I could find was that they were in that book. shrug
(edit to add) In other words, I don't know anything Doissetep or Bellaquin but what you tell me.
Tiana tries to blank her face of emotion (5+ 3 com + 2 guile = 10), but this speech of Rodrigo's has very clearly put her on guard, and she is highly suspicious of him from this point onward. "That is... certainly one opinion," she replies carefully. "Fedora and I shall certainly keep your opinion in mind while we discuss our plans."
OOC: if that's the case, why is it "Convention of the Redcaps" and not "Convention at Andorra"? If it isn't an internal matter why would we not have the entire Andorran council involved in both the preparations and the negotiations?
I'm not really sure how to have Tiana respond to this because I don't know how much of this might be just a difference in how you personally interpret House Mercere than the author of HoH:TL.
I don't see how sending non-Mercere out to handle our negotiations with our House to decide our own future would help us. If anything, it shows them that Fedora and Tiana are incapable of managing our own business. If the Mercere truly view the Tremere as a rival, then wouldn't bringing one into a Redcap Convention be seen as betrayal? We can certainly remind the rest of our house that we stand to lose a lot without having to send in our betters to do our jobs for us.
Because it is a convention about Redcaps. And the Redcaps/Mercere are the ones who make the decision. And you two are part of that. But it is with the covenant as a whole that they are making the deal with, and it makes sense to have an unbiased member of the covenant as part of the final negotiation.
So I guess it is sort of a two part convention, the Mercere gather to discuss what terms they are going to try to bargain for, and the second part is their actually bargaining with the covenant.
As for my interpretation of the Mercere, I am drawing it much in part from True Lineages, but also in part from ToH: Rome (Harco as described in ArM3). True lineages also gave me a sense of their mercenary monetary culture. But I am not so absolute as to say this applies universally. Some Redcaps are like that, others are not. Just like there are good Quaesitores and bad ones, noble Tremere and the power mad, heroic Flambeau as well as destructive hotheads, etcetera.
I am also thinking of what is good for this saga, which takes precedence over the exact wording of any rule books. I want to get this player involved in this story, and I see it as being a valuable asset. I really think it is a good idea, not only because I think he would be good for negotiations, but also because I think it would be fun for the player and give his character a chance to develop politically in an area I think is beneficial for the saga as a whole.
And House Mercere was not invented by Erik Dahl. He contributed much to it, but the originator is Nicole Lindroos Frein.
I appreciate trying to get more players involved in more stories, but I really don't think it makes sense in character to have a non-Mercere magus in negotiations for the Mercer House. If he's doing our talking for us, then we are telling House Mercere not only that Fedora and Tiana can't do their own jobs, we're also telling them that House business, if left to carry on at Andorra, will always be overseen by their rivals. That's a lose-lose situation.
It makes no sense not to, especially considering the credentials and influence he brings to the table. And he will not be negotiating for the Mercere, he is negotiating with them. Tiana and Fedora are negotiating for and with them them.
Your other conclusions are incorrect as they are based on a misunderstanding of your own role. The Redcaps are on one side, the covenant (represented by Vocis) is on the other side. Tiana and Fedora are on both sides, the go-betweens.
"Very well," Tiana tells Vocis. "I'll leave you to your business. You may call upon me if my services are required." She excuses herself, giving an inscrutable look to Fedora, and leaves the Phoenix Sword with Vocis.
Rodrigo rolls his eyes 
What's her problem?
Then turning to Fedora...
Anyway, I imagine their negotiation strategy will work something like this. The other Mercere will see you as their inside contact. Which you are. And they will want to get a good deal, which you will set up for them.
They will throw questions of "why should we stay here?" at you just to throw you off guard and put themselves in a strong bargaining position. Try to deflect these as well as you can, prepare ahead of time how you can respond.
Allay their security fears. Point out how the Mercere quarter was untouched. Come up with a three point plan on how to improve security. Or five point, or whatever. Make it look well organized and clearly though out. Make it sellable. Offer to supply security staff at our expense. Offer them the right to set up an adjacent or secondary Aegis over their section. Brainstorm some ideas.
Then comes the bite, and that's where Vocis comes in. Play good cop / bad cop with them. They will want to renegotiate terms if they stay. That's fair. But hold firm on certain limits. The even ratio on vis exchange, this is the singular most important part of the contract. The monetary rent is trivial mundane silver. Discount deeply have to, but don't give it away free. Cover expenses at the very least.
Maybe play around with the mutual fringe benefit aspects. They always used to give us inside deals on the stuff Redcaps trade in, like lab texts and tractate. We always gave them access to our scribal staff and general library. Occasionally they would contract Longevity Rituals or magic items from us. Stuff like that. Use these as bargaining chips as you will. Offer better or threaten to take some away. Play good cop /bad cop.
And don't fake it either. Vocis, stand your ground and be determined. Fedora, be true to your House but emote your sympathy for the covenant's position.
Tiana, she seems to be determined to handle this as an internal matter of House Mercere. Let her do that, and do that first. When the delegates get here (next week?), let her conference with the Redcaps and see if they can come to quickly accept certain terms, or at least convince them to approach Vocis with some form of contract.
As I told you, getting them to stay is the easy part. They want this already. The question is "at what terms?".
Vocis can play the hard line, which is why it is essential that the covenant put forth a non-Mercere representative.
Fedora, I suppose your role is to make this a signable contract. Arbitrate, compromise, make it work.
Two things. The first is in character: A former Mercere apprentice with low self esteem who lost her Gift works really hard at being a Redcap; she just got told by her superior within the House "No, really, let the Gifted magus take care of it, you're not qualified to do your own job, this outsider can handle it." The second is OOC: that rant of Rodrigo's made Ryu sit back and go Oh sh*t, "Rodrigo" might be Khyron.
Rodrigo is not a superior. He is the ghost (genie) of a legendary Mercere magus from recent history. But can no longer be considered mortal or a magus.
But the rest you will have to deal with in character and grow and develop. It isn't a matter of Vocis being a gifted magus, though I can see how Tiana might see that. It is more important that Vocis is not a member of the Mercere, so he can play the hard line on behalf of the covenant.
Rodrigo's rant freaked you out because it has a speck of truth 
As for Khyron, all I can say is that long ago, at the end of the "Arc of Fire" story, I promised those players that I would never use Khyron again. Of those players, Fixer and Andrew Gronosky remain.
However, I do have a long term goal of convincing you guys to form an expedition to the City of Brass
Fédora sits straighter and looks at Rodrigo through narrowed eyes. [color=blue]"While I certainly respect your experience, and welcome your knowledge of the previous Mercere House here, I must disagree with your assessment that we need to include a sodalis from another House in our discussions of Mercere business. I especially disagree that it should be someone from House Tremere, a House that is by your own words our House's greatest rival. I'm certain that I can't be the only one who suspects him of having a conflict of interest. I have no problem with him participating in the negotiation between us, as representatives of House Mercere's interests in Andorra, and the Covenant Council. But I see no reason to include a Tremere in a meeting of House Mercere, where we discuss and decide Mercere matters, and decide where to place a Mercere House. Or do all Houses invite anyone and everyone to participate in their internal discussions and have a say in how that House is run? My desire is to strike a bargain that will enable us to keep the Mercere House here.
"And I certainly resent your implication that I need a Tremere to put steel in my spine. I am quite capable of handling my affairs, as well as those of the Mercere House and of House Mercere if need be. I will assume that all those decades you spent sequestered in your sword has dulled your recollection of how strong women, especially women of House Mercere, can be, and will forgive you what is undoubtedly a momentary lapse in judgment. But I will not be belittled again."
((I confess that I was also apparently misunderstanding the sequence and intent of these meetings. I was under the impression that the titular "Convention of the Redcaps" was just that – a meeting of the Redcaps from the three Tribunals (and possibly beyond) to decide where to establish the Mercere House, with Fédora and Tiana making a case for keeping it here. Which entailed a previous meeting (even part of a regular Council meeting) to work out with the Council of Andorra a treaty of sorts to establish the Mercere House.
Fédora listens to Rodrigo, her lips growing tighter. [color=blue]"You're right, Father, I don't know what got into me, thinking that I would know the first thing about how to negotiate with others, let alone try to strike a favorable bargain."
Okay, now you too. Look. If you don't want my help, just say so. The delegates will be here Monday. What do you propose is a better plan?
[color=blue]"I didn't say I didn't want your help," Fédora says. [color=blue]"What I want is for you to treat us with respect and not like we're little children."
((Will we have the opportunity to do a little "flashback" type thing and do the negotiations between Fédora, Tiana, and Rodrigo (hereinafter referred to as "The Redcaps") and the rest of the Andorran council (hereinafter referred to as "Those other guys")?))
Yes
((placeholder. I'm feeling run-down, like I'm fighting off something, so it'll be a day or two before I can post a really effective opening statement.))