Everyone knows Heidi. But who knows Johanna Spyri, her inventor? The documentary film "Heidis nightmare" (Heidis Alptraum (German title) / Le cauchemar de Heidi (French title) looks behind the Heidi cliche and undertakes a search for traces in the life and work of the Zurich writer. A journey with, amongst others, Japanese animator Yoichi Kotabe (character designer an...