In this world, death is no longer final. This is thanks to the Mysteri Group, a corporation that has invented the Soul Cloud, a large network of servers that can store the memories and even the soul of the deceased. People may now live on in the Soul Cloud after their death, and their loved ones may visit and communicate with them.
In Master Reboot, the player controls a newcomer to the Soul Cloud, whose upload has somehow gone awry. This person is now without their memories, and must explore the Soul Cloud to find out who they are and what led to their upload, all while being stalked by a rogue security program called seren.exe. By solving puzzles and collecting memories throughout the game's 34 environments, the player can solve the mysteries of what happened to the main character and seren.