There's been a murder in Barcelona. The police can't figure it out and time is ticking. Are you up for the challenge? With photos and a city map, you go into the city, looking for the right locations. At each location you take a group selfie and receive a new clue. Step by step you are getting closer to the truth. Waiting on the way thinking - and doing assignments. With the thinking assignments you collect letters, with the doing assignments you discover where those letters belong in the final code. It’s all about collaboration, sharp thinking and a bit of guts. Can you solve the murder within three hours? In the meantime, you will discover surprising places you would normally pass by. This is no ordinary city walk, but an interactive experience that you experience together.