The Undercity is a bustling realm beneath the earth, gained by way of Nazif's Scents in the Grand Bazaar. This labyrinthine expanse boasts a great stone hall dressed with carpets and a spirited market peopled by tieflings, half-orcs, and half-elves. Its fabric of old stone walls and arches is lit by lamps of many kinds, and breathes a lively air throughout. The Undercity stands a refuge for such as are accursed or altered by magic, and affords a fellowship among those who dwell there.
The descent from Nazif's shop brings one at once into the thick of its life. Local guards direct the newcomer to the Arraf Tavern, the natural first stage of any exploration. There one may meet Kore, a singer who discourses upon Sufism and the welcome owed to the non-human, and so opens a road to other residents and to an understanding of the ways of the Undercity. A coin-pass of the Undercity, given by Kore, eases passage within this realm, and confirms its name as a haven for those upon the margins of society.
The Undercity is marked by dim passages and hidden markets where a various company — merchants and alchemists among them — pursue their trade. The air below is cool and damp, a contrast to the bustle above. Among its notable houses stand the Thieves Bazaar, where poisons, forged identities, and articles of magic change hands, and a cramped shop of rare books kept by a tiefling proprietor. The Undercity furnishes, too, such needful services as healing draughts and enchanted wares, though the prices run steep — a fair token of the intricate commerce and society of this buried haven.
Narrow and winding alleys and closely-packed buildings further mark the Undercity, making of it a very maze. It is peopled by inhabitants of every sort, from children and youths bent to petty crime to grown thieves and footpads. These ply their trades under the eye of an enigmatic chief known as the Ghost of March. The air rings often with the sounds of quarrel and of unlawful dealing, in the manner of a community that governs itself for the most part and looks warily upon any authority from without.
Among its notable figures move Sidra al-Najjar, Jean-Zera Mongé, Gizem Faruki, and Miray, who threaded the close alleys in search of a perfumer's shop. In the course of their wandering they fell in with a Frank, and were thereupon set upon by footpads — an Ejder, an orc, and a tiefling among them. The affray grew hot, with blows and workings of magic on either side, and Ahmet was for a time turned into a fox. Chief among the perils was Usta Kerim, a dwarf who led the band and dealt Sidra a wound. After sundry exchanges the party mastered several of their assailants and treated with the youths yet under Usta Kerim's sway. They saw the children brought to safe lodging, with the help of a certain Kore, whose connexions run through the Undercity. The rule of the Undercity, beneath the hand of the Ghost of March, holds a semblance of order amidst the tumult, and shows the place for what it is — a refuge for such as flee the oppressions of the upper city.
Later discoveries reveal the Undercity to be no haven of the living alone, but a dark expanse besides, of ancient stonework and a labyrinthine plan. It holds divers chambers, some keeping the remains of former occupants — among them an Undead Priest that devoured the corpses of its brother priests. The air lies thick with damp and the scent of decay, whilst a hole in the ceiling betokens some passage to the surface. Its denizens number sundry undead and seekers of treasure alike, such as Hayriah, an East African captain of tomb-robbers, and her crew. The Undercity serves as a storehouse of ancient relics and of dark secrets, as the presence of guardians and of potent artifacts attests — among them a casket with broken chains and runic wards. Its threats include scorpions, undead sentinels, and armed men under Hayriah, who demand the yielding-up of stolen goods. The Undercity figures too in encounters of weight, as with a Vampire that gathered itself from a cold mist and was in the end destroyed; and a ghostly figure named Radu the Handsome gave thanks for the defeat of his brother. The Undercity is a very nest of intrigue and danger, with a meeting yet in prospect with the Ghost of March. Notable sites within it include a Laboratory and an Armory.
Further exploration has laid bare a web of hidden passages and venues, the Hippodrome among them, a ground for chariot-races. The Hippodrome boasts a great central space for spectators and is steeped in an enchantment that works upon the whole arena whilst leaving its stonework untouched. The people of the Undercity number Chique Manu, a wealthy bookmaker, and Cyrus, a grey-bearded dwarf druid who keeps a shop for the selling of beads. At the Hippodrome a Green-team chariot faltered as a spectral horse weakened, to the vexation of the crowd; and an elven woman was observed to work a necrotic debilitation upon a spectral horse in the stables, which hinted at sabotage bound up with Chique Manu.
Besides these, the Styx Bathhouse has been marked as another house of the Undercity, with its great common pool and private rooms, a resort for the making of connexions and the trading of rumour. Its keeper, Hussein, furnishes insight into the local ways and commends the place for ease and for the gathering of intelligence. Of late a compound within the Undercity has been discovered, with an open arched gate held by an orcish figure and a halfling in fatigues after the Sekban cut. Its plan mingles open-air and enclosed rooms — spaces for strategy, a yard for drill, and chambers for conference — and presents a modern military face. Rooms of strategy display the maps of old battles, marking a force styled a modernised "new army" in the Sekban mould. The compound holds a cafeteria besides, where uniformed recruits, likely non-human, share their meals, the aromas of fresh bread and stew mingling with the reek of gunfire and of spent powder. The recruits busy themselves with firearms-drill and with talk of strategy. Alemdar Mustafa Pasha, the bandaged captain reputed the dead Sekban commander, speaks of the need for unity among the factions and lays before the company a journal belonging to Osman, inviting them to send likely recruits to the new Sekban Army. Throughout, the political temper insists upon a nice keeping-up of appearances touching the enmity of the Janissaries and the Sekban.