Plan is related to Plot. Plot is a synonym of Scheme. Scheme is a synonym of Conspiracy. Conspiracy is a type of Agreement. 
Farmer is related to Harm. Killing can be used for Harm. Killing can cause/lead to Guilt. 
Plan <--RelatedTo--> Plot <--Synonym--> Scheme <--Synonym--> Conspiracy --IsA--> Agreement 
Farmer <--RelatedTo--> Harm <--UsedFor-- Killing --Causes--> Guilt 