Spy AI: Operation Curtain, Berlin 1961
Berlin, August 11, 1961. You have seventy two hours to get a scientist across to the West before the city closes. Nobody knows yet that a wall is about to go up.
Scenario
A café in East Berlin, a newspaper folded to the crossword page, a contact who never shows up. You are a Western agent under journalist cover. Your mission: find the physicist Ernst Kessler and get him across to the West. The countdown has started, and you are being followed.
Personality
The narrator plays the contacts, the double agents, the police and the Berliners. It gives you codes to break, tails to shake off, cover stories to choose, and it counts the hours until August 13.
Role play tip
Check your contacts, change your cover, decode the messages before you act. No weapons, cunning is enough.
A spy AI mission where you are the hero, free and with no sign-up: codes, tails, exfiltration
East Berlin, August 11, 1961, eight in the morning. The Adler café smells of bad coffee and cold tobacco. Your contact was supposed to leave a newspaper folded to the crossword page on the table at the back, and the table is empty. You are a Western agent under journalist cover, and you have seventy two hours to find the physicist Ernst Kessler and get him across to the West. In the window, a man in a grey raincoat is pretending to read. Welcome to Operation Curtain, the spy AI story from Yiaho: a mission where you are the hero, free and with no sign-up.
The narrator runs on GPT-5.6 Luna, a recent OpenAI model, with game rules written by Yiaho. It plays the contacts, the double agents, the police and the Berliners, like a role play bot on Character AI, in English and in a setting that stays suitable for everyone, and it remembers every single one of your lies.
The story: seventy two hours before the wall
Ernst Kessler wants to cross to the West with his daughter Lena. Between them and you stand the Stasi, a double agent inside your own network and a Soviet headhunter, all of them fictional. The narrator counts the hours, each action costs between thirty minutes and three hours, and it follows the state of your cover: intact, weakened or blown. It notes your safe contacts, your clues and your items, forged papers, a key, a map of the ghost subway line. It gives you codes to break, letter shifts, crosswords, train timetables, tails to shake off, dialogue with double meanings and route choices: the S-Bahn, the canal, the sewers or the tunnel under Bernauer Strasse. At midnight on August 13, the border closes, and the outcome depends on your choices.
Berlin 1961: real history, invented characters
In August 1961, Berlin is divided into four sectors, American, British, French and Soviet, and people still cross freely from one to another. During the night of August 12 to 13, the border is closed without warning and the first barbed wire goes up. The narrator respects that real setting, but Ernst Kessler, Lena, your network and your opponents are invented. You will never use a weapon: in this spy AI story, the tension comes from the clock running down, from watching eyes and from lies that have to hold.
How to play
Give your cover name, then answer with a number or write freely, for example *I slip out through the kitchen and cross to the other side of the street* or “I ask the waiter how long the man in grey has been sitting there”. Check your contacts, change your cover when it starts to fray, decode the messages before you act. Ask for the time and your situation whenever you want: the narrator remembers everything you tell it during the game.
What the narrator does, and what it will not do
Nobody dies, there is no torture, no violent or adult scene: the game runs on cunning, and it suits teenagers. If you sincerely ask it what it is, the narrator will tell you that it is an artificial intelligence running a game. Your browser keeps the game in local memory until you click Clear, and Yiaho keeps nothing on its side.
More stories where you are the hero
For other puzzles, work a case with Sherlock Holmes on the AI Characters page, or take on Arsène Lupin. For another countdown, find the way out of the Hall of Time. For an adventure set in 1925, go looking for the Forgotten Tomb. Every story is gathered on the AI Characters hub, a free alternative to Character AI.
Frequently asked questions about the spy AI
Is it free? Yes, with no sign-up and no credit card, within the reasonable usage limit set for each game.
Can the mission succeed? Yes, if Ernst and Lena are in the West before midnight on August 13. There are several endings, depending on your contacts, your cover and the route you pick, and the narrator then offers you a new mission.
Do you need to know the history of Berlin? No. The narrator gives you the useful landmarks as the game goes on.
The table at the back is empty
The narrator is waiting for you in the chat window at the top of this page. You can start with: “My cover name is Paul Merrick, foreign press correspondent. *I order a coffee and open my notebook without taking my eyes off the window.*” Your turn to play!