Ada had not intended to turn into Shadow Street at all today, but something was pulling her there. The sun was already hiding behind the rooftops and the city was getting quieter. Philip, her younger brother, was trotting along beside her, glancing at his watch every now and then. "Do we have time?" - he asked uncertainly. "Sure." - replied Ada, although she wasn't so sure herself. Shadow Street was narrow, with cobblestones that sunk unevenly under their feet. But what really caught their attention appeared just around the corner: a clock shop where every window was filled with hundreds of ticking hands and pendulums. One glance at the signboard was enough: "Clockmaker Arkadius. Time not for everyone." Philip shook his eyes. "What does that mean?" - he whispered. Ada didn't know. The door to the shop squeaked as she pushed it open. Inside there was a smell of dust, metal and something hard to identify. There were plenty of clocks - from tiny pocket-sized ones to huge ones standing all the way up to the ceiling. Each ticked with its own rhythm, as if it were in another world. Behind the counter sat an elderly man in a velvet waistcoat and with glasses on the tip of his nose. He stopped fixing something and looked at them penetratingly. "What are you looking for?" - he asked in a voice that sounded appropriate for someone who knows how to talk to time. Ada and Philip exchanged a communicative glance. The shop seemed stranger and stranger. On the wall they flashed clocks without numbers, with the hands twisted, and one pendulum clock was going... backwards. The man pointed to the door behind the counter. "There are worlds undreamed of by the children of this street," he said quietly. "But sometimes someone finds the key." At that moment, something clicked under Ada's feet. Soft blue smoke began to rise from the floor and the clocks seemed to stop in an instant. Philip grabbed her hand. They froze - just before the door leading to the unknown, when the sound of a completely different, unfamiliar world came from inside....