Katya and Dima carefully crept toward the library when the girl suddenly turned around. Something white was slowly coming down the stairs, looking like a ghost from a horror film. One more second, and the whole house would have woken up from her scream, but Dima caught her in time—clamping her mouth shut with his hand—and dragged his partner behind the couch. When she came to, the girl realized she had dropped the paper with the next clue—hard-won in the process—telling where to look for treasure. The white shadow slid along the wall toward the exit of the house, and the two rushed to search for the precious scrap of paper. But the sheet vanished without a trace…