The Butterfly Sign is a first person detective story putting players in shoes of the lone survivor and the only witness to a disastrous incident. The protagonist’s destiny depends on his memories. That is why he dares to take a desperate measure. He takes an experimental drug "Rammex" which immerses him in the depths of his mind and precisely restores all the events occurred to him. In his memories, the protagonist will discover the ones responsible for the disaster, collecting clues bit by bit…