When a Soviet schoolgirl discovers a portal between Moscow and Paris, her quest for escape becomes a journey through time, friendship, and the secrets of parallel realities.

Moscow, 1988. Thirteen-year-old Zoya Kassatkina endures relentless bullying from her classmate Vlasov and dreams of a life beyond her prestigious school near Moscow Zoo. When she mysteriously travels to modern-day Paris during a fainting spell, she befriends Annick, a French girl her own age, and experiences a world of freedom she's never known.

But each journey between worlds comes at a cost. The sinister psychiatrist, Dr. de Vigny, seems to be tracking her movements, and Zoya must unravel the connection between her visions and reality before the portal closes forever. With the help of her intellectual friend Alexei and an unexpected alliance with her former tormentor Vlasov, Zoya races to understand the truth—is she time traveling, dreaming, or slipping between parallel dimensions?