The Parts 4 and 5 update is the largest content drop in The Butchery since the original release. It introduces the open-air Garden and caps the campaign in the climactic Barn Showdown.
The shift from claustrophobic interiors to a forested exterior completely resets player expectations. Stealth learned in Parts 1 to 3 becomes largely obsolete against aggro-linked Chicken swarms.
For the wiki, this update adds two new parts, four new entities, two new weapons (Hunting Rifle and Shotgun retuning), and a final boss encounter that requires every earlier inventory decision to pay off.