Willingness is a type of Emotion. Emotion is related to Tough. Tough is related to Difficult. Difficult is similar to Serious. 
Atmosphere is related to Smoke. Smoke is related to Dark. Alley can be Dark. you are likely to find Rat in/at/on Alley. 
Willingness --IsA--> Emotion <--RelatedTo--> Tough <--RelatedTo--> Difficult <--SimilarTo--> Serious 
Atmosphere <--RelatedTo--> Smoke <--RelatedTo--> Dark <--HasProperty-- Alley <--AtLocation-- Rat 