You find yourself, Portia, Viola, Aetos, and Gregorius, in a storeroom--a very large storeroom, in a very old covenant in Constantinople. Portia, who arrived a few weeks ago, stands face to face with the covenant's autocrat, attempting to stare down the very annoyed-looking middle-aged man. The rest of you arrived only within the past week, at the beginning of spring in 1226, answering a call from the Tribunal of Thebes for volunteers to establish a covenant that will act as a base camp for Hermetic expeditions north and east of the Euxine (as the Romans called the Black Sea). Having made the social rounds of the covenant for a few days, and been congratulated by its members in a grand feast at which your band was presented with the covenant's charter, you've arrived here to get down to the business of packing.
Since you arrived, the autocrat and Portia have been conducting a heated discussion in muffled tones. The autocrat, apparently close to losing his temper, raises his voice: "With all due respect, ma'am, we simply haven't the means to secure additional supplies. It's taken five years since the Tribunal of 1221 to gather enough contributions from the Thebes' covenants to provide you with what we do have--and you certainly didn't help matters by demanding the Tribunal supply you with 64 pawns of vis instead of lab equipment; I personally know a few glassblowers who are miffed at the loss of a potential commission. If you don't leave now, you'll still be preparing by the time the Tribunal of 1227 is held."
The autocrat gestures around him. "You've got enough food for 25 people for a year, building tools, and the beginnings of a decent library. We've arranged to send a dozen covenfolk with you, plus whatever shield grogs you've brought, and staked you to a queen of vis." He glances sideways for a moment to glare at Portia. "We've also hired a ship to convey you to the proposed site at the mouth of the Don." After giving a few orders to covenfolk, the autocrat turns to go, leaving you to begin your journey.
The trip around the eastern edge of the Black Sea, past the Kerch Strait (Cimmerian Bosporus) and its ancient Greek settlement, and up the Sea of Azov (Maeotis in Greek), finally alighting near the mouth of the Don River, at the ruins of the Greek city of Tanais--and of a previous covenant.
Your information on the location is disappointingly sketchy. History records that the site was settled first by the fierce Amazons, at the point where Tanais, son of the Amazon Lysippe, threw himself into the river, after which he was worshipped as a god. The city was later colonized by the Greeks and then Romans, who dwelled there until 330 AD, when it was sacked by the Goths, who destroyed a significant temple to Neptune.
The previous covenant was established in 1208, and seemed to be doing well. Surviving records indicate that a vast aura, extending for miles around, with a level of five at the center of the covenant and in a system of caves formed by underground rivers, as well a number of promising vis sources. Despite this promising start, the covenant vanished suddenly in 1211. A number of grogs and other covenfolk survived the attack that destroyed it, and reported an assault by raiders of uknown origin; the magi were never heard from again.
The Tribunal has suggested this site for the for three reasons. First, it's extensive aura in and of itself makes this location a reasonable one. Second, the magi of Thebes are eager to recover any ancient secrets of Tanais and its temple to Neptune, not to mention the earlier Amazon inhabitants. Third, the Tribunal would really like to know what happened to first covenant, and whether whatever it was poses a threat to the rest of the Tribunal, or indeed the Order.
Scouts sent by the Tribunal brought back both good and bad news. On the positive side, they discovered a single former grog living on the grounds; he's been living there since 1211, and has, entirely by himself, rebuilt several of the covenant's buildings (they were all ruined in the attack). On the negative side, the aura at the center of the covenant has somehow dropped to three, an unfortunate circumstance that led some of those organizing your expedition to suggest trying to find another site.
The ship disembarks you at a fishing village a little ways west of the ruined covenant, on the northern edge of the Don delta, where the locals regard you with considerable suspicion. Despite their unease, they agree after a little bartering to transport your party and its supplies by boat six or seven miles up a small distributary stream of the Don to the ruins of Tanais. The ground around is mostly marshy to the south, across the channel from the ruins, with drier plains and a forest to the north.
What happens next?