Unknown is related to Stranger. you are likely to find Stranger in/at/on Store. 
Employ is related to Pay. Pay is related to Cash. Cash is related to Change. Receive is a type of Change. 
Unknown <--RelatedTo--> Stranger --AtLocation--> Store 
Employ <--RelatedTo--> Pay <--RelatedTo--> Cash <--RelatedTo--> Change <--IsA-- Receive 