Napoleon changes his mind and decides to build a windmill, pretending that it was his idea all along. The first windmill they build collapses. Napoleon blames this (and other problems) on Snowball. He claims that Snowball is sneaking around Animal Farm ruining everything. Many animals are killed for "being in contact with Snowball". Napoleon starts working with human beings outside, even though this used to be forbidden. One of them is their neighbour, a farmer called Mr Frederick. He brings in a group of men who invade the farm and destroy the second windmill. The animals fight them off in the "Battle of the Windmill", at great cost.