Three Bags Full (1949)

George Hardy, a shepherd who loves his sheep and raises them only for their wool. Every night he reads aloud a murder mystery, pretending his sheep can understand, never suspecting that not only can they understand, but they argue for hours afterwards about whodunnit. When George is found dead under mysterious circumstances, the sheep realise at once that it was a murder and think they know everything about how to go about solving it. The local cop Tim Derry, on the other hand, has never solved a serious crime in his life, so the sheep conclude they will have to solve it themselves, even if it means leaving their meadow for the first time and facing the fact that the human world isn’t as simple as it appears in books.