In Opalin, just across the river that no one had bathed in for years any more, stood the Old Brickworks. Surrounded by scrubby bushes and traces of time, it was a place about which parents used to say, ‘Stay away’. However, for fourteen-year-old Maja and her three friends – Antek, Zuza and Luke – it was places like this that were most interesting. It was a sultry July evening when they overheard the conversation of the elders. Someone returning from fishing swore they saw a bright light flashing in the ruins of the brickyard, and strange, low sounds carried through the night. That same evening, hidden under an oak tree, they agreed on a plan: the following day they would explore the brickyard on their own. When they arrived, the ominous building seemed even larger than in the legends. Broken roof tiles were scattered around, and someone had left fresh shoe marks in the sand. ‘Someone has been here recently,’ Maja remarked in a whisper. Antek pulled out a torch and looked around carefully. ‘Look at this!’ He pointed to a section of the wall where someone had recently drawn a strange symbol resembling a combination of a compass and an eye. Zuza, who always carried a notebook, quickly sketched the sign. ‘Maybe it’s some kind of warning?’ she muttered nervously. Maja gathered her courage and walked closer to the window, through which the pale rays of the sun were streaming in. From the cellar came the murmuring. For a moment no one spoke. Luke bent down and picked up a small key from the ground. It was old, heavy, and the same strange symbol was engraved on the end of it. ‘The question is…’ Antek began when suddenly a louder thud came from the cellar and some kind of shadow flitted against the wall. Everyone held their breath. ‘Are we going down there?’ Maja finally asked, clutching the key in her hand. They didn’t hear the answer because then…