In the 1960s and ‘70s, communist Bulgaria had a celebrated animation studio, with Donyo Donev its leading light. His short films delighted viewers at home and abroad. But, as revealed in this documentary, the true creative force behind these works was his “assistant” animator, “Uncle Tony” Antoni Trayanov. More troublingly, the documentary avers that Donev and other senior figures at the studio were in league with the Bulgarian secret police. Mina Mileva and Vesela Kazakova’s impassioned documentary — now a flashpoint of controversy in Bulgaria, after a record-setting theatrical run in Sofia, more than 40 festivals and ten International awards — tells a story of communist-era state control and corruption, but one with widespread relevance to the world of creative collaboration and credit-taking.