Is there a world exactly like ours? Until their mother disappeared, the Greystones had no idea about another dimension. This place is very dangerous, and it was in its trap that my mother fell. The guys are sure that if we don’t get her out of there as soon as possible, big trouble will happen. But how to do this when the only clue is a strange, confusing code? And even the quick-witted Emma, after three hundred and seventy-two attempts, could not solve it... Will the Greystones be able to get into the mirror world and save their mother before the irreparable happens? For everyone who loves intricate mysterious stories in the spirit of “Stranger Things”!