To investigate the disturbance in The Weasel at Apollodorus’ Estate in Assassin’s Creed: Origins climb the pigeon tower to the platform at the back. Interact with the blood stain on the ground, the brazier on the ground and the pieces of wood and blood on the ground. Go to below where the brazier was on the ground and investigate the charcoal. Go to the area below the broken railing and interact with the blood and pieces of wood on the ground there. Turn around, go past the haystack and towards the hay cart. Interact with the hay cart. .
As found on Youtube