When second-grader Marisha found a state-of-the-art mobile phone under her swing, she didn’t know that a year and a half later she would find herself a character in a fantasy story. What would you say if they called you and asked you to talk to yourself in the future? Probably decided that someone was playing a prank on you. This is exactly what Marisha thought when she answered a strange call from an unfamiliar number. But her friend Pertsev is delighted! Call your future self? Ask what will happen in eleven years? What opportunities are opening up! You can know in advance what will happen and not make mistakes. Or prevent road accidents and save people. And most importantly, you can help adults Valery and Marina solve a riddle whose origins lie in the past.