Sack is related to Brown. Brown is related to Bear. Bear is related to Scary. Scary is related to Storm. 
Friend is a different concept from Stranger. you are likely to find Stranger in/at/on City. 
Sack <--RelatedTo--> Brown <--RelatedTo--> Bear <--RelatedTo--> Scary <--RelatedTo--> Storm 
Friend <--DistinctFrom--> Stranger --AtLocation--> City 