The rain drummed against the roof of the old city library as Lena, Igor and Michal crept between the rows of dusty bookcases. It was two o'clock, the library had been closed for hours, and they were - officially - searching the archives as part of a history project. Unofficially, however, they were drawn to the legend of a secret room hidden somewhere at the back of the building. - 'I told you this was a stupid idea,' whispered Igor as they passed under the damp-swollen ceiling. - 'We shouldn't be here. Lena laughed quietly. - You always complain when things get interesting. - She raised her torch and stopped the light on the wall where a framed portrait of a stranger librarian hung. Suddenly Michael, who was rummaging around a heavy bookcase, knelt down and pulled down one of the books. They heard a quiet clatter and a sliding mechanism. The bookcase vibrated and then swung open, revealing a narrow passage. For a moment neither of them spoke. Then Michael smiled broadly, his brown eyes flashing in the torchlight. - It seemed there was a secret here after all. In the stuffy, dark corridor, the air seemed thicker and the sounds of the storm outside the walls quieted. After walking for a while, they reached a door covered with intricate patterns. When Lena touched the handle, she felt something pierce her with a slight shudder. The door swung open on its own, and behind it.... A silvery mist stretched where the wall should have been. Within it, geometric constructions, fragments of bridges and staircases, hung in a completely different reality. There was no floor, only winding paths that disappeared into the mist. The air vibrated with a strange energy. - It's... impossible," whispered Igor. As Lena put her hand out towards the mist, the world around her shook and she felt as if something - or someone - was watching them from beyond the known reality. A human-shaped shadow emerged from the mist and their watches began to walk backwards. - Are we going back in time? - Michael looked at the hands in disbelief. The shadow slowly approached them, and something resembling a city turned upside down appeared behind his back. With every step the shadow took, fragments of mist began to pulsate with light. Suddenly, the corridor behind them slammed shut with a bang, and Lena felt a cold shiver run down her spine. Should they go further in? Is the shadow an enemy or a guide? A whole new world stretched out in front of them, and the return was no longer obvious....