One day, instead of finding yourself where you’re supposed to be, you wake atop a great stone slab. There’s a feeling of missing time, a blackout experienced, and all the accompanying trepidation. Your mind clears, and in front of you, there’s a pair of immense black marble statues - sphinxes - guarding the path that leads to the temple atop the hill that rises before your eyes. Twin voices address you in a calm, androgynous tone, and they offer an explanation of sorts, but no real answers.

“Welcome to Dualis,” they say.

They won’t clarify on why or how you’ve been brought to this city, or even where exactly Dualis is located, only that you have been brought here and it's for a purpose. They tell you to continue on inside the temple; 'the Head' awaits your presence. Any questions are just answered with increasingly louder repititions of "The Head Knows."

Continuing inside, you travel a dimly-illuminated corridor, before finally coming to a vast room filled with blue light that seems to come from everywhere and nowhere all at once. The light pulses and fades, and another calm, androgynous voice greets you, your bones vibrating with the sound in a not unpleasant fashion. It is the Head, it tells you, an AI created millennia ago by the greatest minds in Dualis. Those minds were able to make the Head to run all the city's automated systems, to be its bank and its power grid, its hospitals and hygro-farms, but they were unable to stop their ultimate fate: a plague which decimated the entire population in the blink of an eye. Even the Head in all of its knowledge was powerless to stop the ravages of this disease; no matter how it tried, a decade later, it was alone in this city, the last of the original population having evacuated through the very device that summoned you here.

That very device, it tells you, could be the salvation of Dualis. It thinks that it has finally, finally discovered the source of the corruption in the city, the progenitor of the disease, but in order to cure it, it requires new DNA, new genetic codes to help craft a cure and ensure that no future citizens of Dualis are ever taken by this plague again. Which is why it has brought you here. It needs your help, it says. It needs your presence in the city, so that it may study you and use its data to craft a cure and bring its citizens home again. It won't be forever; only a year by the native calendar. Just a year, and then you can go home knowing you've done your part to save an entire species. Or, you can stay, and help rebuild Dualis to its former glory. The choice will be yours. Unfortunately, you have to remain for the full year, as it will take at least that long to realign the coordinates with your home universe.

In the meantime, you will be cared for, and the city of Dualis is a vibrant and thriving one, with centuries of past volunteers having made their homes within it. Your basic necessities will be cared for, including food and housing. There’s a room prepared for you in the dormitory in the center of the sprawling city; a thumbprint scan will grant you access. You'll be given a personal communication device, as well as access to the Dualis Network once you arrive. After this, the Head conveys its apologies, but it's already taken too much time from its main processes and it has to say goodbye for now, and thanks you again for your sacrifice.

As you exit, the voices from the statues claim that this city is a peaceful one, and they assure you that you’ll be quite content in your new home. You make your way to the dormitory block. You begin, bit by bit, to settle in, make yourself as much at home as possible, a stranger in a puzzling new land. Fellow foreigners, along with the native inhabitants, are your neighbors now; perhaps eventually they will become your friends, your lovers, your allies, your enemies. Together, you begin to assemble clues, common ideas, theories, all in an effort to unravel the mystery at the center of the city.

As for the city itself, Dualis seems pieced together in a patchwork of your collective consciousness, foreign and yet vaguely familiar in parts. Here a neighborhood - did you dream about it as a child? There a district - did you read about this in a history book?

Does the city shift, ever so slightly, from time to time, or is it merely your imagination? Do you sometimes catch a glimpse of a stranger with your face, or is it only a trick of your eyes? And is everything in this city as idyllic as it seems, or is there some sinister, hidden force at work?

There’s more than one way to find out the answers to these questions, and more - but which path will you choose, and where will it lead?