The Red Fox by Anthony Hyde

A Canadian researcher agrees to help a former lover find her missing father, a quest that draws him from Ottawa across Europe and into the Soviet Union. As he follows a trail of memoirs, archives, and shadowy operatives, he uncovers a labyrinth of Cold War espionage entwined with White Russian émigrés, Bolshevik gold, and betrayals reaching back to the Revolution. The case becomes a reckoning with personal and political history, revealing the dangerous price of loyalty and the long echo of buried secrets.